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Michael JP, Putt AD, Yang Y, Adams BG, McBride KR, Fan Y, Lowe KA, Ning D, Jagadamma S, Moon JW, Klingeman DM, Zhang P, Fu Y, Hazen TC, Zhou J. Reproducible responses of geochemical and microbial successional patterns in the subsurface to carbon source amendment. Water Res 2024; 255:121460. [PMID: 38552495 DOI: 10.1016/j.watres.2024.121460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 03/10/2024] [Accepted: 03/11/2024] [Indexed: 04/24/2024]
Abstract
Carbon amendments designed to remediate environmental contamination lead to substantial perturbations when injected into the subsurface. For the remediation of uranium contamination, carbon amendments promote reducing conditions to allow microorganisms to reduce uranium to an insoluble, less mobile state. However, the reproducibility of these amendments and underlying microbial community assembly mechanisms have rarely been investigated in the field. In this study, two injections of emulsified vegetable oil were performed in 2009 and 2017 to immobilize uranium in the groundwater at Oak Ridge, TN, USA. Our objectives were to determine whether and how the injections resulted in similar abiotic and biotic responses and their underlying community assembly mechanisms. Both injections caused similar geochemical and microbial succession. Uranium, nitrate, and sulfate concentrations in the groundwater dropped following the injection, and specific microbial taxa responded at roughly the same time points in both injections, including Geobacter, Desulfovibrio, and members of the phylum Comamonadaceae, all of which are well established in uranium, nitrate, and sulfate reduction. Both injections induced a transition from relatively stochastic to more deterministic assembly of microbial taxonomic and phylogenetic community structures based on 16S rRNA gene analysis. We conclude that geochemical and microbial successions after biostimulation are reproducible, likely owing to the selection of similar phylogenetic groups in response to EVO injection.
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Affiliation(s)
- Jonathan P Michael
- Institute for Environmental Genomics, University of Oklahoma, Norman, OK, USA; School of Biological Sciences, University of Oklahoma, Norman, OK, USA
| | - Andrew D Putt
- Department of Earth and Planetary Sciences, University of Tennessee, Knoxville, TN, USA
| | - Yunfeng Yang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, China
| | - Benjamin G Adams
- Department of Earth and Planetary Sciences, University of Tennessee, Knoxville, TN, USA
| | - Kathryn R McBride
- Department of Microbiology, University of Tennessee, Knoxville, TN, USA
| | - Yupeng Fan
- Institute for Environmental Genomics, University of Oklahoma, Norman, OK, USA; School of Biological Sciences, University of Oklahoma, Norman, OK, USA
| | - Kenneth A Lowe
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Daliang Ning
- Institute for Environmental Genomics, University of Oklahoma, Norman, OK, USA; School of Biological Sciences, University of Oklahoma, Norman, OK, USA
| | - Sindhu Jagadamma
- Biosystems Engineering and Soil Science, University of Tennessee, Knoxville, TN, USA
| | - Ji Won Moon
- National Minerals Information Center, United States Geological Survey, Reston, VA, USA
| | - Dawn M Klingeman
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Ping Zhang
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA
| | - Ying Fu
- Institute for Environmental Genomics, University of Oklahoma, Norman, OK, USA; School of Biological Sciences, University of Oklahoma, Norman, OK, USA
| | - Terry C Hazen
- Department of Earth and Planetary Sciences, University of Tennessee, Knoxville, TN, USA; Department of Microbiology, University of Tennessee, Knoxville, TN, USA; Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA; Department of Civil and Environmental Sciences, University of Tennessee, Knoxville, TN, USA; Institute for a Secure and Sustainable Environment, University of Tennessee, Knoxville, TN, USA
| | - Jizhong Zhou
- Institute for Environmental Genomics, University of Oklahoma, Norman, OK, USA; School of Biological Sciences, University of Oklahoma, Norman, OK, USA; School of Civil Engineering and Environmental Sciences, University of Oklahoma, Norman, OK, USA; Earth and Environmental Sciences, Lawrence Berkley National Laboratory, Berkeley, CA, USA.
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Mulay SA, Hahn CR, Klingeman DM, Elshahed MS, Youssef NH, Podar M. Metagenomic sequencing of a Patescibacteria-containing enrichment from Zodletone spring in Oklahoma, USA. Microbiol Resour Announc 2024; 13:e0011424. [PMID: 38497626 PMCID: PMC11008151 DOI: 10.1128/mra.00114-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Accepted: 03/06/2024] [Indexed: 03/19/2024] Open
Abstract
An enrichment of sulfidic sediments from Zodletone spring was sequenced as a metagenome. Draft genomes representing Cloacimonadota, Deltabacterota, Firmicutes, and Patescibacteria were binned and annotated and will aid functional genomics and cultivation efforts.
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Affiliation(s)
- Sayali A. Mulay
- Department of Microbiology, University of Tennessee Knoxville, Knoxville, Tennessee, USA
| | - C. Ryan Hahn
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Dawn M. Klingeman
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Mostafa S. Elshahed
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Noha H. Youssef
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Mircea Podar
- Department of Microbiology, University of Tennessee Knoxville, Knoxville, Tennessee, USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
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3
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Argiroff WA, Carrell AA, Klingeman DM, Dove NC, Muchero W, Veach AM, Wahl T, Lebreux SJ, Webb AB, Peyton K, Schadt CW, Cregger MA. Seasonality and longer-term development generate temporal dynamics in the Populus microbiome. mSystems 2024; 9:e0088623. [PMID: 38421171 PMCID: PMC10949431 DOI: 10.1128/msystems.00886-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Accepted: 02/08/2024] [Indexed: 03/02/2024] Open
Abstract
Temporal variation in community composition is central to our understanding of the assembly and functioning of microbial communities, yet the controls over temporal dynamics for microbiomes of long-lived plants, such as trees, remain unclear. Temporal variation in tree microbiomes could arise primarily from seasonal (i.e., intra-annual) fluctuations in community composition or from longer-term changes across years as host plants age. To test these alternatives, we experimentally isolated temporal variation in plant microbiome composition using a common garden and clonally propagated plants, and we used amplicon sequencing to characterize bacterial/archaeal and fungal communities in the leaf endosphere, root endosphere, and rhizosphere of two Populus spp. over four seasons across two consecutive years. Microbial community composition differed among seasons and years (which accounted for up to 21% of the variation in microbial community composition) and was correlated with seasonal dissimilarity in climatic conditions. However, microbial community dissimilarity was also positively correlated with time, reflecting longer-term compositional shifts as host trees aged. Together, our findings demonstrate that temporal patterns in tree microbiomes arise from both seasonal fluctuations and longer-term changes, which interact to generate unique seasonal patterns each year. In addition to shedding light on two important controls over the assembly of plant microbiomes, our results also suggest future studies of tree microbiomes should account for background temporal dynamics when testing the drivers of spatial patterns in microbial community composition and temporal responses of plant microbiomes to environmental change.IMPORTANCEMicrobiomes are integral to the health of host plants, but we have a limited understanding of the factors that control how the composition of plant microbiomes changes over time. Especially little is known about the microbiome of long-lived trees, relative to annual and non-woody plants. We tested how tree microbiomes changed between seasons and years in poplar (genus Populus), which are widespread and ecologically important tree species that also serve as important biofuel feedstocks. We found the composition of bacterial, archaeal, and fungal communities differed among seasons, but these seasonal differences depended on year. This dependence was driven by longer-term changes in microbial composition as host trees developed across consecutive years. Our findings suggest that temporal variation in tree microbiomes is driven by both seasonal fluctuations and longer-term (i.e., multiyear) development.
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Affiliation(s)
- William A. Argiroff
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Alyssa A. Carrell
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Dawn M. Klingeman
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Nicholas C. Dove
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Wellington Muchero
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Allison M. Veach
- Department of Integrative Biology, The University of Texas, San Antonio, Texas, USA
| | - Toni Wahl
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Steven J. Lebreux
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Amber B. Webb
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Kellie Peyton
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Christopher W. Schadt
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, USA
| | - Melissa A. Cregger
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
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4
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Podar NA, Carrell AA, Cassidy KA, Klingeman DM, Yang Z, Stahler EA, Smith DW, Stahler DR, Podar M. From wolves to humans: oral microbiome resistance to transfer across mammalian hosts. mBio 2024; 15:e0334223. [PMID: 38299854 PMCID: PMC10936156 DOI: 10.1128/mbio.03342-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 12/21/2023] [Indexed: 02/02/2024] Open
Abstract
The mammalian mouth is colonized by complex microbial communities, adapted to specific niches, and in homeostasis with the host. Individual microbes interact metabolically and rely primarily on nutrients provided by the host, with which they have potentially co-evolved along the mammalian lineages. The oral environment is similar across mammals, but the diversity, specificity, and evolution of community structure in related or interacting mammals are little understood. Here, we compared the oral microbiomes of dogs with those of wild wolves and humans. In dogs, we found an increased microbial diversity relative to wolves, possibly related to the transition to omnivorous nutrition following domestication. This includes a larger diversity of Patescibacteria than previously reported in any other oral microbiota. The oral microbes are most distinct at bacterial species or strain levels, with few if any shared between humans and canids, while the close evolutionary relationship between wolves and dogs is reflected by numerous shared taxa. More taxa are shared at higher taxonomic levels including with humans, supporting their more ancestral common mammalian colonization followed by diversification. Phylogenies of selected oral bacterial lineages do not support stable human-dog microbial transfers but suggest diversification along mammalian lineages (apes and canids). Therefore, despite millennia of cohabitation and close interaction, the host and its native community controls and limits the assimilation of new microbes, even if closely related. Higher resolution metagenomic and microbial physiological studies, covering a larger mammalian diversity, should help understand how oral communities assemble, adapt, and interact with their hosts.IMPORTANCENumerous types of microbes colonize the mouth after birth and play important roles in maintaining oral health. When the microbiota-host homeostasis is perturbed, proliferation of some bacteria leads to diseases such as caries and periodontitis. Unlike the gut microbiome, the diversity of oral microbes across the mammalian evolutionary space is not understood. Our study compared the oral microbiomes of wild wolves, dogs, and apes (humans, chimpanzees, and bonobos), with the aim of identifying if microbes have been potentially exchanged between humans and dogs as a result of domestication and cohabitation. We found little if any evidence for such exchanges. The significance of our research is in finding that the oral microbiota and/or the host limit the acquisition of exogenous microbes, which is important in the context of natural exclusion of potential novel pathogens. We provide a framework for expanded higher-resolution studies across domestic and wild animals to understand resistance/resilience.
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Affiliation(s)
- Nicholas A. Podar
- School of Engineering, Vanderbilt University, Nashville, Tennessee, USA
| | - Alyssa A. Carrell
- Biosciences Department, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Kira A. Cassidy
- Yellowstone Center for Resources, National Park Service, Yellowstone National Park, Wyoming, USA
| | - Dawn M. Klingeman
- Biosciences Department, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Zamin Yang
- Biosciences Department, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Erin A. Stahler
- Yellowstone Center for Resources, National Park Service, Yellowstone National Park, Wyoming, USA
| | - Douglas W. Smith
- Yellowstone Center for Resources, National Park Service, Yellowstone National Park, Wyoming, USA
| | - Daniel R. Stahler
- Yellowstone Center for Resources, National Park Service, Yellowstone National Park, Wyoming, USA
| | - Mircea Podar
- Biosciences Department, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
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Roth SW, Griffiths NA, Kolka RK, Oleheiser KC, Carrell AA, Klingeman DM, Seibert A, Chanton JP, Hanson PJ, Schadt CW. Elevated temperature alters microbial communities, but not decomposition rates, during 3 years of in situ peat decomposition. mSystems 2023; 8:e0033723. [PMID: 37819069 PMCID: PMC10654087 DOI: 10.1128/msystems.00337-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Accepted: 08/29/2023] [Indexed: 10/13/2023] Open
Abstract
IMPORTANCE Microbial community changes in response to climate change drivers have the potential to alter the trajectory of important ecosystem functions. In this paper, we show that while microbial communities in peatland systems responded to manipulations of temperature and CO2 concentrations, these changes were not associated with similar responses in peat decomposition rates over 3 years. It is unclear however from our current studies whether this functional resiliency over 3 years will continue over the longer time scales relevant to peatland ecosystem functions.
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Affiliation(s)
- Spencer W. Roth
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Natalie A. Griffiths
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
- Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Randall K. Kolka
- Northern Research Station, USDA Forest Service, Grand Rapids, Minnesota, USA
| | - Keith C. Oleheiser
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
- Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Alyssa A. Carrell
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Dawn M. Klingeman
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Angela Seibert
- Department of Geosciences, Boise State University, Boise, Idaho, USA
| | - Jeffrey P. Chanton
- Department of Earth, Ocean, and Atmospheric Science, Florida State University, Tallahassee, Florida, USA
| | - Paul J. Hanson
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
- Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Christopher W. Schadt
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
- Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, USA
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6
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Mulay SA, Alexander WG, Hahn CR, Klingeman DM, Elshahed MS, Youssef NH, Podar M. Complete Genome Sequence of Desulfomicrobium sp. Strain ZS1 from Zodletone Spring in Oklahoma, USA. Microbiol Resour Announc 2023; 12:e0014523. [PMID: 37052391 DOI: 10.1128/mra.00145-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/14/2023] Open
Abstract
Desulfomicrobium sp. strain ZS1 is an obligate anaerobic, sulfate-reducing member of the Desulfobacterota from Zodletone Spring, an anoxic sulfide-rich spring in southwestern Oklahoma. Its complete genome was sequenced using a combination of Illumina and Oxford Nanopore platforms and encodes 3,364 proteins and 81 RNAs on a single chromosome.
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Affiliation(s)
- Sayali A Mulay
- Department of Microbiology, University of Tennessee Knoxville, Knoxville, Tennessee, USA
| | - William G Alexander
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - C Ryan Hahn
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Dawn M Klingeman
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Mostafa S Elshahed
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Noha H Youssef
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Mircea Podar
- Department of Microbiology, University of Tennessee Knoxville, Knoxville, Tennessee, USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
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Carrell AA, Hicks BB, Sidelinger E, Johnston ER, Jawdy SS, Clark MM, Klingeman DM, Cregger MA. Nitrogen addition alters soil fungal communities, but root fungal communities are resistant to change. Front Microbiol 2023; 13:1033631. [PMID: 36762095 PMCID: PMC9905728 DOI: 10.3389/fmicb.2022.1033631] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 12/16/2022] [Indexed: 01/26/2023] Open
Abstract
Plants are colonized by numerous microorganisms serving important symbiotic functions that are vital to plant growth and success. Understanding and harnessing these interactions will be useful in both managed and natural ecosystems faced with global change, but it is still unclear how variation in environmental conditions and soils influence the trajectory of these interactions. In this study, we examine how nitrogen addition alters plant-fungal interactions within two species of Populus - Populus deltoides and P. trichocarpa. In this experiment, we manipulated plant host, starting soil (native vs. away for each tree species), and nitrogen addition in a fully factorial replicated design. After ~10 weeks of growth, we destructively harvested the plants and characterized plant growth factors and the soil and root endosphere fungal communities using targeted amplicon sequencing of the ITS2 gene region. Overall, we found nitrogen addition altered plant growth factors, e.g., plant height, chlorophyll density, and plant N content. Interestingly, nitrogen addition resulted in a lower fungal alpha diversity in soils but not plant roots. Further, there was an interactive effect of tree species, soil origin, and nitrogen addition on soil fungal community composition. Starting soils collected from Oregon and West Virginia were dominated by the ectomycorrhizal fungi Inocybe (55.8% relative abundance), but interestingly when P. deltoides was grown in its native West Virginia soil, the roots selected for a high abundance of the arbuscular mycorrhizal fungi, Rhizophagus. These results highlight the importance of soil origin and plant species on establishing plant-fungal interactions.
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Affiliation(s)
- Alyssa A. Carrell
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Brittany B. Hicks
- Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, MI, United States
| | - Emilie Sidelinger
- Department of Environmental Engineering and Earth Sciences, Clemson University, Clemson, SC, United States
| | - Eric R. Johnston
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Sara S. Jawdy
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Miranda M. Clark
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Dawn M. Klingeman
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Melissa A. Cregger
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States,*Correspondence: Melissa A. Cregger ✉
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Carrell AA, Cregger MA, Dove NC, Klingeman DM, Schadt CW. Corrigendum. New Phytol 2022; 235:2127. [PMID: 35781272 PMCID: PMC10117558 DOI: 10.1111/nph.18276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 05/25/2022] [Indexed: 06/15/2023]
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Bentley GJ, Narayanan N, Jha RK, Salvachúa D, Elmore JR, Peabody GL, Black BA, Ramirez K, De Capite A, Michener WE, Werner AZ, Klingeman DM, Schindel HS, Nelson R, Foust L, Guss AM, Dale T, Johnson CW, Beckham GT. Corrigendum to "Engineering glucose metabolism for enhanced muconic acid production in Pseudomonas putida KT2440" [Metab. Eng. 59 (2020) 64-75]. Metab Eng 2022; 72:66-67. [PMID: 35240296 DOI: 10.1016/j.ymben.2022.02.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 02/26/2022] [Indexed: 10/19/2022]
Affiliation(s)
- Gayle J Bentley
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Niju Narayanan
- Bioscience Division, MS M888, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - Ramesh K Jha
- Bioscience Division, MS M888, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - Davinia Salvachúa
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Joshua R Elmore
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - George L Peabody
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Brenna A Black
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Kelsey Ramirez
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Annette De Capite
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - William E Michener
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Allison Z Werner
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Dawn M Klingeman
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Heidi S Schindel
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Robert Nelson
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Lindsey Foust
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Adam M Guss
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Taraka Dale
- Bioscience Division, MS M888, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - Christopher W Johnson
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA.
| | - Gregg T Beckham
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA.
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Rodionov DA, Rodionova IA, Rodionov VA, Arzamasov AA, Zhang K, Rubinstein GM, Tanwee TNN, Bing RG, Crosby JR, Nookaew I, Basen M, Brown SD, Wilson CM, Klingeman DM, Poole FL, Zhang Y, Kelly RM, Adams MWW. Transcriptional Regulation of Plant Biomass Degradation and Carbohydrate Utilization Genes in the Extreme Thermophile Caldicellulosiruptor bescii. mSystems 2021; 6:e0134520. [PMID: 34060910 PMCID: PMC8579813 DOI: 10.1128/msystems.01345-20] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 05/04/2021] [Indexed: 11/20/2022] Open
Abstract
Extremely thermophilic bacteria from the genus Caldicellulosiruptor can degrade polysaccharide components of plant cell walls and subsequently utilize the constituting mono- and oligosaccharides. Through metabolic engineering, ethanol and other industrially important end products can be produced. Previous experimental studies identified a variety of carbohydrate-active enzymes in model species Caldicellulosiruptor saccharolyticus and Caldicellulosiruptor bescii, while prior transcriptomic experiments identified their putative carbohydrate uptake transporters. We investigated the mechanisms of transcriptional regulation of carbohydrate utilization genes using a comparative genomics approach applied to 14 Caldicellulosiruptor species. The reconstruction of carbohydrate utilization regulatory network includes the predicted binding sites for 34 mostly local regulators and point to the regulatory mechanisms controlling expression of genes involved in degradation of plant biomass. The Rex and CggR regulons control the central glycolytic and primary redox reactions. The identified transcription factor binding sites and regulons were validated with transcriptomic and transcription start site experimental data for C. bescii grown on cellulose, cellobiose, glucose, xylan, and xylose. The XylR and XynR regulons control xylan-induced transcriptional response of genes involved in degradation of xylan and xylose utilization. The reconstructed regulons informed the carbohydrate utilization reconstruction analysis and improved functional annotations of 51 transporters and 11 catabolic enzymes. Using gene deletion, we confirmed that the shared ATPase component MsmK is essential for growth on oligo- and polysaccharides but not for the utilization of monosaccharides. By elucidating the carbohydrate utilization framework in C. bescii, strategies for metabolic engineering can be pursued to optimize yields of bio-based fuels and chemicals from lignocellulose. IMPORTANCE To develop functional metabolic engineering platforms for nonmodel microorganisms, a comprehensive understanding of the physiological and metabolic characteristics is critical. Caldicellulosiruptor bescii and other species in this genus have untapped potential for conversion of unpretreated plant biomass into industrial fuels and chemicals. The highly interactive and complex machinery used by C. bescii to acquire and process complex carbohydrates contained in lignocellulose was elucidated here to complement related efforts to develop a metabolic engineering platform with this bacterium. Guided by the findings here, a clearer picture of how C. bescii natively drives carbohydrate utilization is provided and strategies to engineer this bacterium for optimal conversion of lignocellulose to commercial products emerge.
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Affiliation(s)
- Dmitry A. Rodionov
- Sanford-Burnhams-Prebys Medical Discovery Institute, La Jolla, California, USA
- A.A. Kharkevich Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, Russia
| | - Irina A. Rodionova
- Department of Bioengineering, University of California—San Diego, La Jolla, California, USA
| | - Vladimir A. Rodionov
- A.A. Kharkevich Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, Russia
| | - Aleksandr A. Arzamasov
- Sanford-Burnhams-Prebys Medical Discovery Institute, La Jolla, California, USA
- A.A. Kharkevich Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, Russia
| | - Ke Zhang
- Department of Cell and Molecular Biology, College of the Environment and Life Sciences, University of Rhode Island, Kingston, Rhode Island, USA
| | - Gabriel M. Rubinstein
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia, USA
| | - Tania N. N. Tanwee
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia, USA
| | - Ryan G. Bing
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina, USA
| | - James R. Crosby
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina, USA
| | - Intawat Nookaew
- Department of Biomedical Informatics, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Mirko Basen
- Mathematisch-Naturwissenschaftliche Fakultät, Institut für Biowissenschaften, Mikrobiologie, Universität Rostock, Rostock, Germany
| | - Steven D. Brown
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Charlotte M. Wilson
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
- University of Otago, Dunedin, New Zealand
| | - Dawn M. Klingeman
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Farris L. Poole
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia, USA
| | - Ying Zhang
- Department of Cell and Molecular Biology, College of the Environment and Life Sciences, University of Rhode Island, Kingston, Rhode Island, USA
| | - Robert M. Kelly
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina, USA
| | - Michael W. W. Adams
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia, USA
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11
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Dove NC, Klingeman DM, Carrell AA, Cregger MA, Schadt CW. Fire alters plant microbiome assembly patterns: integrating the plant and soil microbial response to disturbance. New Phytol 2021; 230:2433-2446. [PMID: 33525047 PMCID: PMC8251558 DOI: 10.1111/nph.17248] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 01/27/2021] [Indexed: 05/06/2023]
Abstract
It is increasingly evident that the plant microbiome is a strong determinant of plant health. While the ability to manipulate the microbiome in plants and ecosystems recovering from disturbance may be useful, our understanding of the plant microbiome in regenerating plant communities is currently limited. Using 16S ribosomal RNA (rRNA) gene and internal transcribed spacer (ITS) region amplicon sequencing, we characterized the leaf, stem, fine root, rhizome, and rhizosphere microbiome of < 1-yr-old aspen saplings and the associated bulk soil after a recent high-intensity prescribed fire across a burn severity gradient. Consistent with previous studies, we found that soil microbiomes are responsive to fire. We extend these findings by showing that certain plant tissue microbiomes also change in response to fire. Differences in soil microbiome compositions could be attributed to soil chemical characteristics, but, generally, plant tissue microbiomes were not related to plant tissue elemental concentrations. Using source tracking modeling, we also show that fire influences the relative dominance of microbial inoculum and the vertical inheritance of the sapling microbiome from the parent tree. Overall, our results demonstrate how fire impacts plant microbiome assembly, diversity, and composition and highlights potential for further research towards increasing plant fitness and ecosystem recovery after fire events.
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Affiliation(s)
- Nicholas C. Dove
- Biosciences DivisionOak Ridge National LaboratoryOak RidgeTN37831USA
| | - Dawn M. Klingeman
- Biosciences DivisionOak Ridge National LaboratoryOak RidgeTN37831USA
| | - Alyssa A. Carrell
- Biosciences DivisionOak Ridge National LaboratoryOak RidgeTN37831USA
| | - Melissa A. Cregger
- Biosciences DivisionOak Ridge National LaboratoryOak RidgeTN37831USA
- Department of Ecology and Evolutionary BiologyUniversity of TennesseeKnoxvilleTN37996USA
| | - Christopher W. Schadt
- Biosciences DivisionOak Ridge National LaboratoryOak RidgeTN37831USA
- Department of MicrobiologyUniversity of TennesseeKnoxvilleTN37996USA
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12
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Elmore JR, Dexter GN, Salvachúa D, Martinez-Baird J, Hatmaker EA, Huenemann JD, Klingeman DM, Peabody GL, Peterson DJ, Singer C, Beckham GT, Guss AM. Production of itaconic acid from alkali pretreated lignin by dynamic two stage bioconversion. Nat Commun 2021; 12:2261. [PMID: 33859194 PMCID: PMC8050072 DOI: 10.1038/s41467-021-22556-8] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 03/17/2021] [Indexed: 02/02/2023] Open
Abstract
Expanding the portfolio of products that can be made from lignin will be critical to enabling a viable bio-based economy. Here, we engineer Pseudomonas putida for high-yield production of the tricarboxylic acid cycle-derived building block chemical, itaconic acid, from model aromatic compounds and aromatics derived from lignin. We develop a nitrogen starvation-detecting biosensor for dynamic two-stage bioproduction in which itaconic acid is produced during a non-growth associated production phase. Through the use of two distinct itaconic acid production pathways, the tuning of TCA cycle gene expression, deletion of competing pathways, and dynamic regulation, we achieve an overall maximum yield of 56% (mol/mol) and titer of 1.3 g/L from p-coumarate, and 1.4 g/L titer from monomeric aromatic compounds produced from alkali-treated lignin. This work illustrates a proof-of-principle that using dynamic metabolic control to reroute carbon after it enters central metabolism enables production of valuable chemicals from lignin at high yields by relieving the burden of constitutively expressing toxic heterologous pathways.
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Affiliation(s)
- Joshua R. Elmore
- grid.135519.a0000 0004 0446 2659Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN USA ,grid.451303.00000 0001 2218 3491Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA USA
| | - Gara N. Dexter
- grid.135519.a0000 0004 0446 2659Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN USA
| | - Davinia Salvachúa
- grid.419357.d0000 0001 2199 3636National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO USA
| | - Jessica Martinez-Baird
- grid.135519.a0000 0004 0446 2659Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN USA
| | - E. Anne Hatmaker
- grid.135519.a0000 0004 0446 2659Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN USA
| | - Jay D. Huenemann
- grid.135519.a0000 0004 0446 2659Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN USA ,grid.411461.70000 0001 2315 1184Bredesen Center for Interdisciplinary Research, University of Tennessee, Knoxville, TN USA
| | - Dawn M. Klingeman
- grid.135519.a0000 0004 0446 2659Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN USA
| | - George L. Peabody
- grid.135519.a0000 0004 0446 2659Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN USA
| | - Darren J. Peterson
- grid.419357.d0000 0001 2199 3636National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO USA
| | - Christine Singer
- grid.419357.d0000 0001 2199 3636National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO USA
| | - Gregg T. Beckham
- grid.419357.d0000 0001 2199 3636National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO USA
| | - Adam M. Guss
- grid.135519.a0000 0004 0446 2659Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN USA ,grid.411461.70000 0001 2315 1184Bredesen Center for Interdisciplinary Research, University of Tennessee, Knoxville, TN USA
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13
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Carrell AA, Schwartz GE, Cregger MA, Gionfriddo CM, Elias DA, Wilpiszeski RL, Klingeman DM, Wymore AM, Muller KA, Brooks SC. Nutrient Exposure Alters Microbial Composition, Structure, and Mercury Methylating Activity in Periphyton in a Contaminated Watershed. Front Microbiol 2021; 12:647861. [PMID: 33815336 PMCID: PMC8017159 DOI: 10.3389/fmicb.2021.647861] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 02/22/2021] [Indexed: 01/04/2023] Open
Abstract
The conversion of mercury (Hg) to monomethylmercury (MMHg) is a critical area of concern in global Hg cycling. Periphyton biofilms may harbor significant amounts of MMHg but little is known about the Hg-methylating potential of the periphyton microbiome. Therefore, we used high-throughput amplicon sequencing of the 16S rRNA gene, ITS2 region, and Hg methylation gene pair (hgcAB) to characterize the archaea/bacteria, fungi, and Hg-methylating microorganisms in periphyton communities grown in a contaminated watershed in East Tennessee (United States). Furthermore, we examined how nutrient amendments (nitrate and/or phosphate) altered periphyton community structure and function. We found that bacterial/archaeal richness in experimental conditions decreased in summer and increased in autumn relative to control treatments, while fungal diversity generally increased in summer and decreased in autumn relative to control treatments. Interestingly, the Hg-methylating communities were dominated by Proteobacteria followed by Candidatus Atribacteria across both seasons. Surprisingly, Hg methylation potential correlated with numerous bacterial families that do not contain hgcAB, suggesting that the overall microbiome structure of periphyton communities influences rates of Hg transformation within these microbial mats. To further explore these complex community interactions, we performed a microbial network analysis and found that the nitrate-amended treatment resulted in the highest number of hub taxa that also corresponded with enhanced Hg methylation potential. This work provides insight into community interactions within the periphyton microbiome that may contribute to Hg cycling and will inform future research that will focus on establishing mixed microbial consortia to uncover mechanisms driving shifts in Hg cycling within periphyton habitats.
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Affiliation(s)
- Alyssa A Carrell
- Oak Ridge National Laboratory, Biosciences Division, Oak Ridge, TN, United States
| | - Grace E Schwartz
- Oak Ridge National Laboratory, Environmental Science Division, Oak Ridge, TN, United States.,Department of Chemistry, Wofford College, Spartanburg, SC, United States
| | - Melissa A Cregger
- Oak Ridge National Laboratory, Biosciences Division, Oak Ridge, TN, United States
| | - Caitlin M Gionfriddo
- Oak Ridge National Laboratory, Biosciences Division, Oak Ridge, TN, United States.,Smithsonian Environmental Research Center, Edgewater, MD, United States
| | - Dwayne A Elias
- Oak Ridge National Laboratory, Biosciences Division, Oak Ridge, TN, United States
| | - Regina L Wilpiszeski
- Oak Ridge National Laboratory, Biosciences Division, Oak Ridge, TN, United States
| | - Dawn M Klingeman
- Oak Ridge National Laboratory, Biosciences Division, Oak Ridge, TN, United States
| | - Ann M Wymore
- Oak Ridge National Laboratory, Biosciences Division, Oak Ridge, TN, United States
| | - Katherine A Muller
- Pacific Northwest National Laboratory, Earth Systems Science Division, Richland, WA, United States
| | - Scott C Brooks
- Oak Ridge National Laboratory, Environmental Science Division, Oak Ridge, TN, United States
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14
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Notonier S, Werner AZ, Kuatsjah E, Dumalo L, Abraham PE, Hatmaker EA, Hoyt CB, Amore A, Ramirez KJ, Woodworth SP, Klingeman DM, Giannone RJ, Guss AM, Hettich RL, Eltis LD, Johnson CW, Beckham GT. Metabolism of syringyl lignin-derived compounds in Pseudomonas putida enables convergent production of 2-pyrone-4,6-dicarboxylic acid. Metab Eng 2021; 65:111-122. [PMID: 33741529 DOI: 10.1016/j.ymben.2021.02.005] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 02/14/2021] [Accepted: 02/22/2021] [Indexed: 12/15/2022]
Abstract
Valorization of lignin, an abundant component of plant cell walls, is critical to enabling the lignocellulosic bioeconomy. Biological funneling using microbial biocatalysts has emerged as an attractive approach to convert complex mixtures of lignin depolymerization products to value-added compounds. Ideally, biocatalysts would convert aromatic compounds derived from the three canonical types of lignin: syringyl (S), guaiacyl (G), and p-hydroxyphenyl (H). Pseudomonas putida KT2440 (hereafter KT2440) has been developed as a biocatalyst owing in part to its native catabolic capabilities but is not known to catabolize S-type lignin-derived compounds. Here, we demonstrate that syringate, a common S-type lignin-derived compound, is utilized by KT2440 only in the presence of another energy source or when vanAB was overexpressed, as syringate was found to be O-demethylated to gallate by VanAB, a two-component monooxygenase, and further catabolized via extradiol cleavage. Unexpectedly, the specificity (kcat/KM) of VanAB for syringate was within 25% that for vanillate and O-demethylation of both substrates was well-coupled to O2 consumption. However, the native KT2440 gallate-cleaving dioxygenase, GalA, was potently inactivated by 3-O-methylgallate. To engineer a biocatalyst to simultaneously convert S-, G-, and H-type monomers, we therefore employed VanAB from Pseudomonas sp. HR199, which has lower activity for 3MGA, and LigAB, an extradiol dioxygenase able to cleave protocatechuate and 3-O-methylgallate. This strain converted 93% of a mixture of lignin monomers to 2-pyrone-4,6-dicarboxylate, a promising bio-based chemical. Overall, this study elucidates a native pathway in KT2440 for catabolizing S-type lignin-derived compounds and demonstrates the potential of this robust chassis for lignin valorization.
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Affiliation(s)
- Sandra Notonier
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA; Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | - Allison Z Werner
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA; Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | - Eugene Kuatsjah
- Department of Microbiology and Immunology, BioProducts Institute, and the Life Sciences Institute, The University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Linda Dumalo
- Department of Microbiology and Immunology, BioProducts Institute, and the Life Sciences Institute, The University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Paul E Abraham
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA; Oak Ridge National Laboratory, 1 Bethel Valley Rd, Oak Ridge, TN, 37830, USA
| | - E Anne Hatmaker
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA; Oak Ridge National Laboratory, 1 Bethel Valley Rd, Oak Ridge, TN, 37830, USA
| | - Caroline B Hoyt
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Antonella Amore
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Kelsey J Ramirez
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Sean P Woodworth
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Dawn M Klingeman
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA; Oak Ridge National Laboratory, 1 Bethel Valley Rd, Oak Ridge, TN, 37830, USA
| | - Richard J Giannone
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA; Oak Ridge National Laboratory, 1 Bethel Valley Rd, Oak Ridge, TN, 37830, USA
| | - Adam M Guss
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA; Oak Ridge National Laboratory, 1 Bethel Valley Rd, Oak Ridge, TN, 37830, USA
| | - Robert L Hettich
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA; Oak Ridge National Laboratory, 1 Bethel Valley Rd, Oak Ridge, TN, 37830, USA
| | - Lindsay D Eltis
- Department of Microbiology and Immunology, BioProducts Institute, and the Life Sciences Institute, The University of British Columbia, Vancouver, BC V6T 1Z3, Canada.
| | - Christopher W Johnson
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA.
| | - Gregg T Beckham
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA; Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA.
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15
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Tian R, Ning D, He Z, Zhang P, Spencer SJ, Gao S, Shi W, Wu L, Zhang Y, Yang Y, Adams BG, Rocha AM, Detienne BL, Lowe KA, Joyner DC, Klingeman DM, Arkin AP, Fields MW, Hazen TC, Stahl DA, Alm EJ, Zhou J. Small and mighty: adaptation of superphylum Patescibacteria to groundwater environment drives their genome simplicity. Microbiome 2020; 8:51. [PMID: 32252814 PMCID: PMC7137472 DOI: 10.1186/s40168-020-00825-w] [Citation(s) in RCA: 140] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 03/13/2020] [Indexed: 05/18/2023]
Abstract
BACKGROUND The newly defined superphylum Patescibacteria such as Parcubacteria (OD1) and Microgenomates (OP11) has been found to be prevalent in groundwater, sediment, lake, and other aquifer environments. Recently increasing attention has been paid to this diverse superphylum including > 20 candidate phyla (a large part of the candidate phylum radiation, CPR) because it refreshed our view of the tree of life. However, adaptive traits contributing to its prevalence are still not well known. RESULTS Here, we investigated the genomic features and metabolic pathways of Patescibacteria in groundwater through genome-resolved metagenomics analysis of > 600 Gbp sequence data. We observed that, while the members of Patescibacteria have reduced genomes (~ 1 Mbp) exclusively, functions essential to growth and reproduction such as genetic information processing were retained. Surprisingly, they have sharply reduced redundant and nonessential functions, including specific metabolic activities and stress response systems. The Patescibacteria have ultra-small cells and simplified membrane structures, including flagellar assembly, transporters, and two-component systems. Despite the lack of CRISPR viral defense, the bacteria may evade predation through deletion of common membrane phage receptors and other alternative strategies, which may explain the low representation of prophage proteins in their genomes and lack of CRISPR. By establishing the linkages between bacterial features and the groundwater environmental conditions, our results provide important insights into the functions and evolution of this CPR group. CONCLUSIONS We found that Patescibacteria has streamlined many functions while acquiring advantages such as avoiding phage invasion, to adapt to the groundwater environment. The unique features of small genome size, ultra-small cell size, and lacking CRISPR of this large lineage are bringing new understandings on life of Bacteria. Our results provide important insights into the mechanisms for adaptation of the superphylum in the groundwater environments, and demonstrate a case where less is more, and small is mighty.
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Affiliation(s)
- Renmao Tian
- Department of Microbiology and Plant Biology, Institute for Environmental Genomics, University of Oklahoma, Norman, OK, USA
| | - Daliang Ning
- Department of Microbiology and Plant Biology, Institute for Environmental Genomics, University of Oklahoma, Norman, OK, USA
| | - Zhili He
- Department of Microbiology and Plant Biology, Institute for Environmental Genomics, University of Oklahoma, Norman, OK, USA
| | - Ping Zhang
- Department of Microbiology and Plant Biology, Institute for Environmental Genomics, University of Oklahoma, Norman, OK, USA
| | - Sarah J Spencer
- Biological Engineering Department, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Shuhong Gao
- Department of Microbiology and Plant Biology, Institute for Environmental Genomics, University of Oklahoma, Norman, OK, USA
| | - Weiling Shi
- Department of Microbiology and Plant Biology, Institute for Environmental Genomics, University of Oklahoma, Norman, OK, USA
| | - Linwei Wu
- Department of Microbiology and Plant Biology, Institute for Environmental Genomics, University of Oklahoma, Norman, OK, USA
| | - Ya Zhang
- Department of Microbiology and Plant Biology, Institute for Environmental Genomics, University of Oklahoma, Norman, OK, USA
| | - Yunfeng Yang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, China
| | - Benjamin G Adams
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, TN, USA
| | - Andrea M Rocha
- Oak Ridge National Laboratory, Biosciences Division, Oak Ridge, TN, USA
| | - Brittny L Detienne
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, TN, USA
| | - Kenneth A Lowe
- Oak Ridge National Laboratory, Biosciences Division, Oak Ridge, TN, USA
| | - Dominique C Joyner
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, TN, USA
| | - Dawn M Klingeman
- Oak Ridge National Laboratory, Biosciences Division, Oak Ridge, TN, USA
| | - Adam P Arkin
- Department of Bioengineering, University of California, Berkeley, CA, USA
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Matthew W Fields
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA
| | - Terry C Hazen
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, TN, USA
- Oak Ridge National Laboratory, Biosciences Division, Oak Ridge, TN, USA
| | - David A Stahl
- Department of Civil and Environmental Engineering, University of Washington, Seattle, WA, USA
| | - Eric J Alm
- Biological Engineering Department, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Jizhong Zhou
- Department of Microbiology and Plant Biology, Institute for Environmental Genomics, University of Oklahoma, Norman, OK, USA.
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, China.
- Earth and Environmental Sciences, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
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16
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Sander KB, Chung D, Klingeman DM, Giannone RJ, Rodriguez M, Whitham J, Hettich RL, Davison BH, Westpheling J, Brown SD. Gene targets for engineering osmotolerance in Caldicellulosiruptor bescii. Biotechnol Biofuels 2020; 13:50. [PMID: 32190115 PMCID: PMC7071700 DOI: 10.1186/s13068-020-01690-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Accepted: 02/27/2020] [Indexed: 05/05/2023]
Abstract
BACKGROUND Caldicellulosiruptor bescii, a promising biocatalyst being developed for use in consolidated bioprocessing of lignocellulosic materials to ethanol, grows poorly and has reduced conversion at elevated medium osmolarities. Increasing tolerance to elevated fermentation osmolarities is desired to enable performance necessary of a consolidated bioprocessing (CBP) biocatalyst. RESULTS Two strains of C. bescii showing growth phenotypes in elevated osmolarity conditions were identified. The first strain, ORCB001, carried a deletion of the FapR fatty acid biosynthesis and malonyl-CoA metabolism repressor and had a severe growth defect when grown in high-osmolarity conditions-introduced as the addition of either ethanol, NaCl, glycerol, or glucose to growth media. The second strain, ORCB002, displayed a growth rate over three times higher than its genetic parent when grown in high-osmolarity medium. Unexpectedly, a genetic complement ORCB002 exhibited improved growth, failing to revert the observed phenotype, and suggesting that mutations other than the deleted transcription factor (the fruR/cra gene) are responsible for the growth phenotype observed in ORCB002. Genome resequencing identified several other genomic alterations (three deleted regions, three substitution mutations, one silent mutation, and one frameshift mutation), which may be responsible for the observed increase in osmolarity tolerance in the fruR/cra-deficient strain, including a substitution mutation in dnaK, a gene previously implicated in osmoresistance in bacteria. Differential expression analysis and transcription factor binding site inference indicates that FapR negatively regulates malonyl-CoA and fatty acid biosynthesis, as it does in many other bacteria. FruR/Cra regulates neighboring fructose metabolism genes, as well as other genes in global manner. CONCLUSIONS Two systems able to effect tolerance to elevated osmolarities in C. bescii are identified. The first is fatty acid biosynthesis. The other is likely the result of one or more unintended, secondary mutations present in another transcription factor deletion strain. Though the locus/loci and mechanism(s) responsible remain unknown, candidate mutations are identified, including a mutation in the dnaK chaperone coding sequence. These results illustrate both the promise of targeted regulatory manipulation for osmotolerance (in the case of fapR) and the challenges (in the case of fruR/cra).
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Affiliation(s)
- Kyle B. Sander
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN USA
- Bredesen Center for Interdisciplinary Graduate Research and Education, University of Tennessee, Knoxville, TN USA
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, TN USA
- Present Address: Department of Bioengineering, University of California, Berkeley, Berkeley, CA USA
| | - Daehwan Chung
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN USA
- Department of Genetics, University of Georgia, Athens, GA USA
- Present Address: National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO USA
| | - Dawn M. Klingeman
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN USA
| | - Richard J. Giannone
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN USA
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830 USA
| | - Miguel Rodriguez
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN USA
| | - Jason Whitham
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN USA
- Present Address: Becton Dickinson Diagnostics, Sparks Glencoe, MD USA
| | - Robert L. Hettich
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN USA
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830 USA
| | - Brian H. Davison
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN USA
- Bredesen Center for Interdisciplinary Graduate Research and Education, University of Tennessee, Knoxville, TN USA
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, TN USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN USA
| | - Janet Westpheling
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN USA
- Department of Genetics, University of Georgia, Athens, GA USA
| | - Steven D. Brown
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN USA
- Bredesen Center for Interdisciplinary Graduate Research and Education, University of Tennessee, Knoxville, TN USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN USA
- Present Address: LanzaTech, Skokie, IL USA
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17
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Hatmaker EA, Klingeman DM, Martin RK, Guss AM, Elkins JG. Complete Genome Sequence of Caloramator sp. Strain E03, a Novel Ethanologenic, Thermophilic, Obligately Anaerobic Bacterium. Microbiol Resour Announc 2019; 8:e00708-19. [PMID: 31395644 PMCID: PMC6687931 DOI: 10.1128/mra.00708-19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 07/18/2019] [Indexed: 11/20/2022] Open
Abstract
Here, we report the complete genome sequence of Caloramator sp. strain E03, an anaerobic thermophile that was isolated from a hot spring within the Rabbit Creek area of Yellowstone National Park. The assembly contains a single 2,984,770-bp contig with a G+C content of 31.3% and is predicted to encode 2,678 proteins.
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Affiliation(s)
- E Anne Hatmaker
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Dawn M Klingeman
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
- The Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Roman K Martin
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Adam M Guss
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
- The Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
- Bredesen Center for Interdisciplinary Research and Graduate Education, University of Tennessee-Knoxville, Knoxville, Tennessee, USA
| | - James G Elkins
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
- The Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
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18
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Chen H, Yang ZK, Yip D, Morris RH, Lebreux SJ, Cregger MA, Klingeman DM, Hui D, Hettich RL, Wilhelm SW, Wang G, Löffler FE, Schadt CW. One-time nitrogen fertilization shifts switchgrass soil microbiomes within a context of larger spatial and temporal variation. PLoS One 2019; 14:e0211310. [PMID: 31211785 PMCID: PMC6581249 DOI: 10.1371/journal.pone.0211310] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 05/28/2019] [Indexed: 12/21/2022] Open
Abstract
Soil microbiome responses to short-term nitrogen (N) inputs remain uncertain when compared with previous research that has focused on long-term fertilization responses. Here, we examined soil bacterial/archaeal and fungal communities pre- and post-N fertilization in an 8 year-old switchgrass field, in which twenty-four plots received N fertilization at three levels (0, 100, and 200 kg N ha-1 as NH4NO3) for the first time since planting. Soils were collected at two depths, 0–5 and 5–15 cm, for DNA extraction and amplicon sequencing of 16S rRNA genes and ITS regions for assessment of microbial community composition. Baseline assessments prior to fertilization revealed no significant pre-existing divergence in either bacterial/archaeal or fungal communities across plots. The one-time N fertilizations increased switchgrass yields and tissue N content, and the added N was nearly completely removed from the soil of fertilized plots by the end of the growing season. Both bacterial/archaeal and fungal communities showed large spatial (by depth) and temporal variation (by season) within each plot, accounting for 17 and 12–22% of the variation as calculated from the Sq. root of PERMANOVA tests for bacterial/archaeal and fungal community composition, respectively. While N fertilization effects accounted for only ~4% of overall variation, some specific microbial groups, including the bacterial genus Pseudonocardia and the fungal genus Archaeorhizomyces, were notably repressed by fertilization at 200 kg N ha-1. Bacterial groups varied with both depth in the soil profile and time of sampling, while temporal variability shaped the fungal community more significantly than vertical heterogeneity in the soil. These results suggest that short-term effects of N fertilization are significant but subtle, and other sources of variation will need to be carefully accounted for study designs including multiple intra-annual sampling dates, rather than one-time “snapshot” analyses that are common in the literature. Continued analyses of these trends over time with fertilization and management are needed to understand how these effects may persist or change over time.
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Affiliation(s)
- Huaihai Chen
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
| | - Zamin K. Yang
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
| | - Dan Yip
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
| | - Reese H. Morris
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
| | - Steven J. Lebreux
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
| | - Melissa A. Cregger
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
| | - Dawn M. Klingeman
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
| | - Dafeng Hui
- Department of Biological Sciences, Tennessee State University, Nashville, Tennessee, United States of America
| | - Robert L. Hettich
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, United States of America
| | - Steven W. Wilhelm
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, United States of America
| | - Gangsheng Wang
- Environmental Science Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
- Institute for Environmental Genomics and Department of Microbiology & Plant Biology, University of Oklahoma, Norman, Oklahoma, United States of America
| | - Frank E. Löffler
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, United States of America
| | - Christopher W. Schadt
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, United States of America
- * E-mail:
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19
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Sander K, Chung D, Hyatt D, Westpheling J, Klingeman DM, Rodriguez M, Engle NL, Tschaplinski TJ, Davison BH, Brown SD. Rex in Caldicellulosiruptor bescii: Novel regulon members and its effect on the production of ethanol and overflow metabolites. Microbiologyopen 2019; 8:e00639. [PMID: 29797457 PMCID: PMC6391272 DOI: 10.1002/mbo3.639] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Revised: 03/03/2018] [Accepted: 03/05/2018] [Indexed: 11/23/2022] Open
Abstract
Rex is a global redox-sensing transcription factor that senses and responds to the intracellular [NADH]/[NAD+ ] ratio to regulate genes for central metabolism, and a variety of metabolic processes in Gram-positive bacteria. We decipher and validate four new members of the Rex regulon in Caldicellulosiruptor bescii; a gene encoding a class V aminotransferase, the HydG FeFe Hydrogenase maturation protein, an oxidoreductase, and a gene encoding a hypothetical protein. Structural genes for the NiFe and FeFe hydrogenases, pyruvate:ferredoxin oxidoreductase, as well as the rex gene itself are also members of this regulon, as has been predicted previously in different organisms. A C. bescii rex deletion strain constructed in an ethanol-producing strain made 54% more ethanol (0.16 mmol/L) than its genetic parent after 36 hr of fermentation, though only under nitrogen limited conditions. Metabolomic interrogation shows this rex-deficient ethanol-producing strain synthesizes other reduced overflow metabolism products likely in response to more reduced intracellular redox conditions and the accumulation of pyruvate. These results suggest ethanol production is strongly dependent on the native intracellular redox state in C. bescii, and highlight the combined promise of using this gene and manipulation of culture conditions to yield strains capable of producing ethanol at higher yields and final titer.
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Affiliation(s)
- Kyle Sander
- Department of Chemical and Biomolecular EngineeringUniversity of TennesseeKnoxvilleTennessee
- Bredesen Center for Interdisciplinary Graduate Research and EducationUniversity of TennesseeKnoxvilleTennessee
- BioEnergy Sciences CenterOak Ridge National LaboratoryOak RidgeTennessee
| | - Daehwan Chung
- BioEnergy Sciences CenterOak Ridge National LaboratoryOak RidgeTennessee
- Department of GeneticsUniversity of GeorgiaAthensGeorgia
- Present address:
National Renewable Energy LaboratoryGoldenCO
| | - Doug Hyatt
- BioEnergy Sciences CenterOak Ridge National LaboratoryOak RidgeTennessee
- Biosciences DivisionOak Ridge National LaboratoryOak RidgeTennessee
| | - Janet Westpheling
- BioEnergy Sciences CenterOak Ridge National LaboratoryOak RidgeTennessee
- Department of GeneticsUniversity of GeorgiaAthensGeorgia
| | - Dawn M. Klingeman
- BioEnergy Sciences CenterOak Ridge National LaboratoryOak RidgeTennessee
- Biosciences DivisionOak Ridge National LaboratoryOak RidgeTennessee
| | - Miguel Rodriguez
- BioEnergy Sciences CenterOak Ridge National LaboratoryOak RidgeTennessee
- Biosciences DivisionOak Ridge National LaboratoryOak RidgeTennessee
| | - Nancy L. Engle
- BioEnergy Sciences CenterOak Ridge National LaboratoryOak RidgeTennessee
- Biosciences DivisionOak Ridge National LaboratoryOak RidgeTennessee
| | - Timothy J. Tschaplinski
- BioEnergy Sciences CenterOak Ridge National LaboratoryOak RidgeTennessee
- Biosciences DivisionOak Ridge National LaboratoryOak RidgeTennessee
| | - Brian H. Davison
- Department of Chemical and Biomolecular EngineeringUniversity of TennesseeKnoxvilleTennessee
- Bredesen Center for Interdisciplinary Graduate Research and EducationUniversity of TennesseeKnoxvilleTennessee
- BioEnergy Sciences CenterOak Ridge National LaboratoryOak RidgeTennessee
- Biosciences DivisionOak Ridge National LaboratoryOak RidgeTennessee
| | - Steven D. Brown
- Bredesen Center for Interdisciplinary Graduate Research and EducationUniversity of TennesseeKnoxvilleTennessee
- BioEnergy Sciences CenterOak Ridge National LaboratoryOak RidgeTennessee
- Biosciences DivisionOak Ridge National LaboratoryOak RidgeTennessee
- Present address:
LanzaTechSkokieIL
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20
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Papanek B, O’Dell KB, Manga P, Giannone RJ, Klingeman DM, Hettich RL, Brown SD, Guss AM. Transcriptomic and proteomic changes from medium supplementation and strain evolution in high-yielding Clostridium thermocellum strains. ACTA ACUST UNITED AC 2018; 45:1007-1015. [DOI: 10.1007/s10295-018-2073-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2018] [Accepted: 08/18/2018] [Indexed: 01/05/2023]
Abstract
Abstract
Clostridium thermocellum is a potentially useful organism for the production of lignocellulosic biofuels because of its ability to directly deconstruct cellulose and convert it into ethanol. Previously engineered C. thermocellum strains have achieved higher yields and titers of ethanol. These strains often initially grow more poorly than the wild type. Adaptive laboratory evolution and medium supplementation have been used to improve growth, but the mechanism(s) by which growth improves remain(s) unclear. Here, we studied (1) wild-type C. thermocellum, (2) the slow-growing and high-ethanol-yielding mutant AG553, and (3) the faster-growing evolved mutant AG601, each grown with and without added formate. We used a combination of transcriptomics and proteomics to understand the physiological impact of the metabolic engineering, evolution, and medium supplementation. Medium supplementation with formate improved growth in both AG553 and AG601. Expression of C1 metabolism genes varied with formate addition, supporting the hypothesis that the primary benefit of added formate is the supply of C1 units for biosynthesis. Expression of stress response genes such as those involved in the sporulation cascade was dramatically over-represented in AG553, even after the addition of formate, suggesting that the source of the stress may be other issues such as redox imbalances. The sporulation response is absent in evolved strain AG601, suggesting that sporulation limits the growth of engineered strain AG553. A better understanding of the stress response and mechanisms of improved growth hold promise for informing rational improvement of C. thermocellum for lignocellulosic biofuel production.
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Affiliation(s)
- Beth Papanek
- 0000 0004 0446 2659 grid.135519.a Biosciences Division Oak Ridge National Laboratory Oak Ridge TN USA
- 0000 0001 2315 1184 grid.411461.7 Bredesen Center for Interdisciplinary Research and Graduate Education University of Tennessee-Knoxville Knoxville TN USA
- 0000 0004 1936 9991 grid.35403.31 Integrated Bioprocessing Research Laboratory University of Illinois-Urbana-Champaign Urbana IL USA
| | - Kaela B O’Dell
- 0000 0004 0446 2659 grid.135519.a Biosciences Division Oak Ridge National Laboratory Oak Ridge TN USA
| | - Punita Manga
- 0000 0004 0446 2659 grid.135519.a Biosciences Division Oak Ridge National Laboratory Oak Ridge TN USA
- 0000 0001 2315 1184 grid.411461.7 The Graduate School of Genome Science and Technology University of Tennessee-Knoxville Knoxville TN USA
| | - Richard J Giannone
- 0000 0004 0446 2659 grid.135519.a Biosciences Division Oak Ridge National Laboratory Oak Ridge TN USA
| | - Dawn M Klingeman
- 0000 0004 0446 2659 grid.135519.a Biosciences Division Oak Ridge National Laboratory Oak Ridge TN USA
| | - Robert L Hettich
- 0000 0004 0446 2659 grid.135519.a Biosciences Division Oak Ridge National Laboratory Oak Ridge TN USA
| | - Steven D Brown
- 0000 0004 0446 2659 grid.135519.a Biosciences Division Oak Ridge National Laboratory Oak Ridge TN USA
- 0000 0001 2315 1184 grid.411461.7 The Graduate School of Genome Science and Technology University of Tennessee-Knoxville Knoxville TN USA
- LanzaTech Inc 8045 Lamon Ave, Suite 400 60077 Skokie IL USA
| | - Adam M Guss
- 0000 0004 0446 2659 grid.135519.a Biosciences Division Oak Ridge National Laboratory Oak Ridge TN USA
- 0000 0001 2315 1184 grid.411461.7 Bredesen Center for Interdisciplinary Research and Graduate Education University of Tennessee-Knoxville Knoxville TN USA
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21
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Liang X, Whitham JM, Holwerda EK, Shao X, Tian L, Wu YW, Lombard V, Henrissat B, Klingeman DM, Yang ZK, Podar M, Richard TL, Elkins JG, Brown SD, Lynd LR. Development and characterization of stable anaerobic thermophilic methanogenic microbiomes fermenting switchgrass at decreasing residence times. Biotechnol Biofuels 2018; 11:243. [PMID: 30202438 PMCID: PMC6126044 DOI: 10.1186/s13068-018-1238-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Accepted: 08/27/2018] [Indexed: 06/08/2023]
Abstract
BACKGROUND Anaerobic fermentation of lignocellulose occurs in both natural and managed environments, and is an essential part of the carbon cycle as well as a promising route to sustainable production of fuels and chemicals. Lignocellulose solubilization by mixed microbiomes is important in these contexts. RESULTS Here, we report the development of stable switchgrass-fermenting enrichment cultures maintained at various residence times and moderately high (55 °C) temperatures. Anaerobic microbiomes derived from a digester inoculum were incubated at 55 °C and fed semi-continuously with medium containing 30 g/L mid-season harvested switchgrass to achieve residence times (RT) of 20, 10, 5, and 3.3 days. Stable, time-invariant cellulolytic methanogenic cultures with minimal accumulation of organic acids were achieved for all RTs. Fractional carbohydrate solubilization was 0.711, 0.654, 0.581 and 0.538 at RT = 20, 10, 5 and 3.3 days, respectively, and glucan solubilization was proportional to xylan solubilization at all RTs. The rate of solubilization was described well by the equation r = k(C - C0fr), where C represents the concentration of unutilized carbohydrate, C0 is the concentration of carbohydrate (cellulose and hemicellulose) entering the bioreactor and fr is the extrapolated fraction of entering carbohydrate that is recalcitrant at infinite residence time. The 3.3 day RT is among the shortest RT reported for stable thermophilic, methanogenic digestion of a lignocellulosic feedstock. 16S rDNA phylotyping and metagenomic analyses were conducted to characterize the effect of RT on community dynamics and to infer functional roles in the switchgrass to biogas conversion to the various microbial taxa. Firmicutes were the dominant phylum, increasing in relative abundance from 54 to 96% as RT decreased. A Clostridium clariflavum strain with genetic markers for xylose metabolism was the most abundant lignocellulose-solubilizing bacterium. A Thermotogae (Defluviitoga tunisiensis) was the most abundant bacterium in switchgrass digesters at RT = 20 days but decreased in abundance at lower RTs as did multiple Chloroflexi. Synergistetes and Euryarchaeota were present at roughly constant levels over the range of RTs examined. CONCLUSIONS A system was developed in which stable methanogenic steady-states were readily obtained with a particulate biomass feedstock, mid-season switchgrass, at laboratory (1 L) scale. Characterization of the extent and rate of carbohydrate solubilization in combination with 16S rDNA and metagenomic sequencing provides a multi-dimensional view of performance, species composition, glycoside hydrolases, and metabolic function with varying residence time. These results provide a point of reference and guidance for future studies and organism development efforts involving defined cultures.
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Affiliation(s)
- Xiaoyu Liang
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755 USA
- BioEnergy Sciences Center, Oak Ridge, TN 37830 USA
| | - Jason M. Whitham
- BioEnergy Sciences Center, Oak Ridge, TN 37830 USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830 USA
| | - Evert K. Holwerda
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755 USA
- BioEnergy Sciences Center, Oak Ridge, TN 37830 USA
| | - Xiongjun Shao
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755 USA
- BioEnergy Sciences Center, Oak Ridge, TN 37830 USA
| | - Liang Tian
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755 USA
- BioEnergy Sciences Center, Oak Ridge, TN 37830 USA
| | - Yu-Wei Wu
- Graduate Institute of Biomedical Informatics, College of Medical Science and Technology, Taipei Medical University, Taipei, 106 Taiwan
| | - Vincent Lombard
- CNRS, UMR 7257, Aix-Marseille University, 13288 Marseille, France
- INRA, USC 1408 AFMB, 13288 Marseille, France
| | - Bernard Henrissat
- CNRS, UMR 7257, Aix-Marseille University, 13288 Marseille, France
- INRA, USC 1408 AFMB, 13288 Marseille, France
- Department of Biological Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Dawn M. Klingeman
- BioEnergy Sciences Center, Oak Ridge, TN 37830 USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830 USA
| | - Zamin K. Yang
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830 USA
| | - Mircea Podar
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830 USA
| | - Tom L. Richard
- Department of Agricultural and Biological Engineering, The Pennsylvania State University, University Park, State College, PA 16802 USA
| | - James G. Elkins
- BioEnergy Sciences Center, Oak Ridge, TN 37830 USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830 USA
| | - Steven D. Brown
- BioEnergy Sciences Center, Oak Ridge, TN 37830 USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830 USA
- Present Address: LanzaTech, Inc., Skokie, IL 60077 USA
| | - Lee R. Lynd
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755 USA
- BioEnergy Sciences Center, Oak Ridge, TN 37830 USA
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22
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Whitham JM, Moon JW, Rodriguez M, Engle NL, Klingeman DM, Rydzak T, Abel MM, Tschaplinski TJ, Guss AM, Brown SD. Clostridium thermocellum LL1210 pH homeostasis mechanisms informed by transcriptomics and metabolomics. Biotechnol Biofuels 2018; 11:98. [PMID: 29632556 PMCID: PMC5887222 DOI: 10.1186/s13068-018-1095-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Accepted: 03/24/2018] [Indexed: 05/21/2023]
Abstract
BACKGROUND Clostridium (Ruminiclostridium) thermocellum is a model fermentative anaerobic thermophile being studied and engineered for consolidated bioprocessing of lignocellulosic feedstocks into fuels and chemicals. Engineering efforts have resulted in significant improvements in ethanol yields and titers although further advances are required to make the bacterium industry-ready. For instance, fermentations at lower pH could enable co-culturing with microbes that have lower pH optima, augment productivity, and reduce buffering cost. C. thermocellum is typically grown at neutral pH, and little is known about its pH limits or pH homeostasis mechanisms. To better understand C. thermocellum pH homeostasis we grew strain LL1210 (C. thermocellum DSM1313 Δhpt ΔhydG Δldh Δpfl Δpta-ack), currently the highest ethanol producing strain of C. thermocellum, at different pH values in chemostat culture and applied systems biology tools. RESULTS Clostridium thermocellum LL1210 was found to be growth-limited below pH 6.24 at a dilution rate of 0.1 h-1. F1F0-ATPase gene expression was upregulated while many ATP-utilizing enzymes and pathways were downregulated at pH 6.24. These included most flagella biosynthesis genes, genes for chemotaxis, and other motility-related genes (> 50) as well as sulfate transport and reduction, nitrate transport and nitrogen fixation, and fatty acid biosynthesis genes. Clustering and enrichment of differentially expressed genes at pH values 6.48, pH 6.24 and pH 6.12 (washout conditions) compared to pH 6.98 showed inverse differential expression patterns between the F1F0-ATPase and genes for other ATP-utilizing enzymes. At and below pH 6.24, amino acids including glutamate and valine; long-chain fatty acids, their iso-counterparts and glycerol conjugates; glycolysis intermediates 3-phosphoglycerate, glucose 6-phosphate, and glucose accumulated intracellularly. Glutamate was 267 times more abundant in cells at pH 6.24 compared to pH 6.98, and intercellular concentration reached 1.8 μmol/g pellet at pH 5.80 (stopped flow). CONCLUSIONS Clostridium thermocellum LL1210 can grow under slightly acidic conditions, similar to limits reported for other strains. This foundational study provides a detailed characterization of a relatively acid-intolerant bacterium and provides genetic targets for strain improvement. Future studies should examine adding gene functions used by more acid-tolerant bacteria for improved pH homeostasis at acidic pH values.
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Affiliation(s)
- Jason M. Whitham
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN USA
- BioEnergy Science Center, National Laboratory, Oak Ridge, TN USA
| | - Ji-Won Moon
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN USA
| | - Miguel Rodriguez
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN USA
- BioEnergy Science Center, National Laboratory, Oak Ridge, TN USA
| | - Nancy L. Engle
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN USA
- BioEnergy Science Center, National Laboratory, Oak Ridge, TN USA
| | - Dawn M. Klingeman
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN USA
- BioEnergy Science Center, National Laboratory, Oak Ridge, TN USA
| | - Thomas Rydzak
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN USA
- BioEnergy Science Center, National Laboratory, Oak Ridge, TN USA
- Present Address: Department of Biological Science, University of Calgary, Calgary, AB T2N 1N4 Canada
| | - Malaney M. Abel
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN USA
- BioEnergy Science Center, National Laboratory, Oak Ridge, TN USA
| | - Timothy J. Tschaplinski
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN USA
- BioEnergy Science Center, National Laboratory, Oak Ridge, TN USA
| | - Adam M. Guss
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN USA
- BioEnergy Science Center, National Laboratory, Oak Ridge, TN USA
| | - Steven D. Brown
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN USA
- BioEnergy Science Center, National Laboratory, Oak Ridge, TN USA
- Present Address: LanzaTech, Inc., Skokie, IL USA
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23
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Verbeke TJ, Giannone RJ, Klingeman DM, Engle NL, Rydzak T, Guss AM, Tschaplinski TJ, Brown SD, Hettich RL, Elkins JG. Erratum: Corrigendum: Pentose sugars inhibit metabolism and increase expression of an AgrD-type cyclic pentapeptide in Clostridium thermocellum. Sci Rep 2017; 7:46875. [PMID: 28749932 PMCID: PMC5532492 DOI: 10.1038/srep46875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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24
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Utturkar SM, Klingeman DM, Hurt RA, Brown SD. A Case Study into Microbial Genome Assembly Gap Sequences and Finishing Strategies. Front Microbiol 2017; 8:1272. [PMID: 28769883 PMCID: PMC5513972 DOI: 10.3389/fmicb.2017.01272] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 06/26/2017] [Indexed: 11/20/2022] Open
Abstract
This study characterized regions of DNA which remained unassembled by either PacBio and Illumina sequencing technologies for seven bacterial genomes. Two genomes were manually finished using bioinformatics and PCR/Sanger sequencing approaches and regions not assembled by automated software were analyzed. Gaps present within Illumina assemblies mostly correspond to repetitive DNA regions such as multiple rRNA operon sequences. PacBio gap sequences were evaluated for several properties such as GC content, read coverage, gap length, ability to form strong secondary structures, and corresponding annotations. Our hypothesis that strong secondary DNA structures blocked DNA polymerases and contributed to gap sequences was not accepted. PacBio assemblies had few limitations overall and gaps were explained as cumulative effect of lower than average sequence coverage and repetitive sequences at contig termini. An important aspect of the present study is the compilation of biological features that interfered with assembly and included active transposons, multiple plasmid sequences, phage DNA integration, and large sequence duplication. Our targeted genome finishing approach and systematic evaluation of the unassembled DNA will be useful for others looking to close, finish, and polish microbial genome sequences.
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Affiliation(s)
- Sagar M Utturkar
- Graduate School of Genome Science and Technology, University of TennesseeKnoxville, TN, United States
| | - Dawn M Klingeman
- Biosciences Division, Oak Ridge National LaboratoryOak Ridge, TN, United States.,BioEnergy Science CenterOak Ridge, TN, United States
| | - Richard A Hurt
- Biosciences Division, Oak Ridge National LaboratoryOak Ridge, TN, United States
| | - Steven D Brown
- Graduate School of Genome Science and Technology, University of TennesseeKnoxville, TN, United States.,Biosciences Division, Oak Ridge National LaboratoryOak Ridge, TN, United States.,BioEnergy Science CenterOak Ridge, TN, United States
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25
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Choi J, Klingeman DM, Brown SD, Cox CD. The LacI family protein GlyR3 co-regulates the celC operon and manB in Clostridium thermocellum. Biotechnol Biofuels 2017; 10:163. [PMID: 28652864 PMCID: PMC5483248 DOI: 10.1186/s13068-017-0849-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 06/16/2017] [Indexed: 06/07/2023]
Abstract
BACKGROUND Clostridium thermocellum utilizes a wide variety of free and cellulosomal cellulases and accessory enzymes to hydrolyze polysaccharides present in complex substrates. To date only a few studies have unveiled the details by which the expression of these cellulases are regulated. Recent studies have described the auto regulation of the celC operon and determined that the celC-glyR3-licA gene cluster and nearby manB-celT gene cluster are co-transcribed as polycistronic mRNA. RESULTS In this paper, we demonstrate that the GlyR3 protein mediates the regulation of manB. We first identify putative GlyR3 binding sites within or just upstream of the coding regions of manB and celT. Using an electrophoretic mobility shift assay (EMSA), we determined that a higher concentration of GlyR3 is required to effectively bind to the putative manB site in comparison to the celC site. Neither the putative celT site nor random DNA significantly binds GlyR3. While laminaribiose interfered with GlyR3 binding to the celC binding site, binding to the manB site was unaffected. In the presence of laminaribiose, in vivo transcription of the celC-glyR3-licA gene cluster increases, while manB expression is repressed, compared to in the absence of laminaribiose, consistent with the results from the EMSA. An in vitro transcription assay demonstrated that GlyR3 and laminaribiose interactions were responsible for the observed patters of in vivo transcription. CONCLUSIONS Together these results reveal a mechanism by which manB is expressed at low concentrations of GlyR3 but repressed at high concentrations. In this way, C. thermocellum is able to co-regulate both the celC and manB gene clusters in response to the availability of β-1,3-polysaccharides in its environment.
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Affiliation(s)
- Jinlyung Choi
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, TN 37996 USA
- Center for Environmental Biotechnology, University of Tennessee, Knoxville, TN 37996 USA
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - Dawn M. Klingeman
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - Steven D. Brown
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - Chris D. Cox
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, TN 37996 USA
- Center for Environmental Biotechnology, University of Tennessee, Knoxville, TN 37996 USA
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Department Civil and Environmental Engineering, University of Tennessee, Knoxville, TN 37996 USA
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26
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Rydzak T, Garcia D, Stevenson DM, Sladek M, Klingeman DM, Holwerda EK, Amador-Noguez D, Brown SD, Guss AM. Deletion of Type I glutamine synthetase deregulates nitrogen metabolism and increases ethanol production in Clostridium thermocellum. Metab Eng 2017; 41:182-191. [PMID: 28400329 DOI: 10.1016/j.ymben.2017.04.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 03/27/2017] [Accepted: 04/07/2017] [Indexed: 12/25/2022]
Abstract
Clostridium thermocellum rapidly deconstructs cellulose and ferments resulting hydrolysis products into ethanol and other products, and is thus a promising platform organism for the development of cellulosic biofuel production via consolidated bioprocessing. While recent metabolic engineering strategies have targeted eliminating canonical fermentation products (acetate, lactate, formate, and H2), C. thermocellum also secretes amino acids, which has limited ethanol yields in engineered strains to approximately 70% of the theoretical maximum. To investigate approaches to decrease amino acid secretion, we attempted to reduce ammonium assimilation by deleting the Type I glutamine synthetase (glnA) in an essentially wild type strain of C. thermocellum. Deletion of glnA reduced levels of secreted valine and total amino acids by 53% and 44% respectively, and increased ethanol yields by 53%. RNA-seq analysis revealed that genes encoding the RNF-complex were more highly expressed in ΔglnA and may have a role in improving NADH-availability for ethanol production. While a significant up-regulation of genes involved in nitrogen assimilation and urea uptake suggested that deletion of glnA induces a nitrogen starvation response, metabolomic analysis showed an increase in intracellular glutamine levels indicative of nitrogen-rich conditions. We propose that deletion of glnA causes deregulation of nitrogen metabolism, leading to overexpression of nitrogen metabolism genes and, in turn, elevated glutamine levels. Here we demonstrate that perturbation of nitrogen assimilation is a promising strategy to redirect flux from the production of nitrogenous compounds toward biofuels in C. thermocellum.
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Affiliation(s)
- Thomas Rydzak
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States; BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - David Garcia
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States; BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - David M Stevenson
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, United States
| | - Margaret Sladek
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States; BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Dawn M Klingeman
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States; BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Evert K Holwerda
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States; Thayer School of Engineering at Dartmouth College, Hanover, NH, United States
| | - Daniel Amador-Noguez
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, United States
| | - Steven D Brown
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States; BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Adam M Guss
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States; BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, United States.
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Dumitrache A, Klingeman DM, Natzke J, Rodriguez M, Giannone RJ, Hettich RL, Davison BH, Brown SD. Specialized activities and expression differences for Clostridium thermocellum biofilm and planktonic cells. Sci Rep 2017; 7:43583. [PMID: 28240279 PMCID: PMC5327387 DOI: 10.1038/srep43583] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 01/25/2017] [Indexed: 01/01/2023] Open
Abstract
Clostridium (Ruminiclostridium) thermocellum is a model organism for its ability to deconstruct plant biomass and convert the cellulose into ethanol. The bacterium forms biofilms adherent to lignocellulosic feedstocks in a continuous cell-monolayer in order to efficiently break down and uptake cellulose hydrolysates. We developed a novel bioreactor design to generate separate sessile and planktonic cell populations for omics studies. Sessile cells had significantly greater expression of genes involved in catabolism of carbohydrates by glycolysis and pyruvate fermentation, ATP generation by proton gradient, the anabolism of proteins and lipids and cellular functions critical for cell division consistent with substrate replete conditions. Planktonic cells had notably higher gene expression for flagellar motility and chemotaxis, cellulosomal cellulases and anchoring scaffoldins, and a range of stress induced homeostasis mechanisms such as oxidative stress protection by antioxidants and flavoprotein co-factors, methionine repair, Fe-S cluster assembly and repair in redox proteins, cell growth control through tRNA thiolation, recovery of damaged DNA by nucleotide excision repair and removal of terminal proteins by proteases. This study demonstrates that microbial attachment to cellulose substrate produces widespread gene expression changes for critical functions of this organism and provides physiological insights for two cells populations relevant for engineering of industrially-ready phenotypes.
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Affiliation(s)
- Alexandru Dumitrache
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN, 37831, U.S.A.,Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, U.S.A
| | - Dawn M Klingeman
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN, 37831, U.S.A.,Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, U.S.A
| | - Jace Natzke
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN, 37831, U.S.A.,Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, U.S.A
| | - Miguel Rodriguez
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN, 37831, U.S.A.,Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, U.S.A
| | - Richard J Giannone
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN, 37831, U.S.A.,Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, U.S.A
| | - Robert L Hettich
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN, 37831, U.S.A.,Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, U.S.A
| | - Brian H Davison
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN, 37831, U.S.A.,Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, U.S.A
| | - Steven D Brown
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN, 37831, U.S.A.,Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, U.S.A
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28
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Verbeke TJ, Giannone RJ, Klingeman DM, Engle NL, Rydzak T, Guss AM, Tschaplinski TJ, Brown SD, Hettich RL, Elkins JG. Pentose sugars inhibit metabolism and increase expression of an AgrD-type cyclic pentapeptide in Clostridium thermocellum. Sci Rep 2017; 7:43355. [PMID: 28230109 PMCID: PMC5322536 DOI: 10.1038/srep43355] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Accepted: 01/18/2017] [Indexed: 12/22/2022] Open
Abstract
Clostridium thermocellum could potentially be used as a microbial biocatalyst to produce renewable fuels directly from lignocellulosic biomass due to its ability to rapidly solubilize plant cell walls. While the organism readily ferments sugars derived from cellulose, pentose sugars from xylan are not metabolized. Here, we show that non-fermentable pentoses inhibit growth and end-product formation during fermentation of cellulose-derived sugars. Metabolomic experiments confirmed that xylose is transported intracellularly and reduced to the dead-end metabolite xylitol. Comparative RNA-seq analysis of xylose-inhibited cultures revealed several up-regulated genes potentially involved in pentose transport and metabolism, which were targeted for disruption. Deletion of the ATP-dependent transporter, CbpD partially alleviated xylose inhibition. A putative xylitol dehydrogenase, encoded by Clo1313_0076, was also deleted resulting in decreased total xylitol production and yield by 41% and 46%, respectively. Finally, xylose-induced inhibition corresponds with the up-regulation and biogenesis of a cyclical AgrD-type, pentapeptide. Medium supplementation with the mature cyclical pentapeptide also inhibits bacterial growth. Together, these findings provide new foundational insights needed for engineering improved pentose utilizing strains of C. thermocellum and reveal the first functional Agr-type cyclic peptide to be produced by a thermophilic member of the Firmicutes.
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Affiliation(s)
- Tobin J Verbeke
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.,Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Richard J Giannone
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.,Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Dawn M Klingeman
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.,Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Nancy L Engle
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.,Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Thomas Rydzak
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.,Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Adam M Guss
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.,Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Timothy J Tschaplinski
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.,Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Steven D Brown
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.,Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Robert L Hettich
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.,Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - James G Elkins
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.,Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
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29
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Biswas R, Wilson CM, Giannone RJ, Klingeman DM, Rydzak T, Shah MB, Hettich RL, Brown SD, Guss AM. Improved growth rate in Clostridium thermocellum hydrogenase mutant via perturbed sulfur metabolism. Biotechnol Biofuels 2017; 10:6. [PMID: 28053665 PMCID: PMC5209896 DOI: 10.1186/s13068-016-0684-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Accepted: 12/08/2016] [Indexed: 05/16/2023]
Abstract
BACKGROUND Metabolic engineering is a commonly used approach to develop organisms for an industrial function, but engineering aimed at improving one phenotype can negatively impact other phenotypes. This lack of robustness can prove problematic. Cellulolytic bacterium Clostridium thermocellum is able to rapidly ferment cellulose to ethanol and other products. Recently, genes involved in H2 production, including the hydrogenase maturase hydG and NiFe hydrogenase ech, were deleted from the chromosome of C. thermocellum. While ethanol yield increased, the growth rate of ΔhydG decreased substantially compared to wild type. RESULTS Addition of 5 mM acetate to the growth medium improved the growth rate in C. thermocellum ∆hydG, whereas wild type remained unaffected. Transcriptomic analysis of the wild type showed essentially no response to the addition of acetate. However, in C. thermocellum ΔhydG, 204 and 56 genes were significantly differentially regulated relative to wild type in the absence and presence of acetate, respectively. Genes, Clo1313_0108-0125, which are predicted to encode a sulfate transport system and sulfate assimilatory pathway, were drastically upregulated in C. thermocellum ΔhydG in the presence of added acetate. A similar pattern was seen with proteomics. Further physiological characterization demonstrated an increase in sulfide synthesis and elimination of cysteine consumption in C. thermocellum ΔhydG. Clostridium thermocellum ΔhydGΔech had a higher growth rate than ΔhydG in the absence of added acetate, and a similar but less pronounced transcriptional and physiological effect was seen in this strain upon addition of acetate. CONCLUSIONS Sulfur metabolism is perturbed in C. thermocellum ΔhydG strains, likely to increase flux through sulfate reduction to act either as an electron sink to balance redox reactions or to offset an unknown deficiency in sulfur assimilation.
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Affiliation(s)
- Ranjita Biswas
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830 USA
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37830 USA
- Centre for Rural Development and Technology, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110016 India
| | - Charlotte M. Wilson
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830 USA
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37830 USA
| | - Richard J. Giannone
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37830 USA
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830 USA
| | - Dawn M. Klingeman
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830 USA
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37830 USA
| | - Thomas Rydzak
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830 USA
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37830 USA
| | - Manesh B. Shah
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830 USA
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37830 USA
| | - Robert L. Hettich
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37830 USA
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830 USA
| | - Steven D. Brown
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830 USA
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37830 USA
| | - Adam M. Guss
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830 USA
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37830 USA
- One Bethel Valley Road, Oak Ridge, TN 37831-6038 USA
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30
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Utturkar SM, Cude WN, Robeson MS, Yang ZK, Klingeman DM, Land ML, Allman SL, Lu TYS, Brown SD, Schadt CW, Podar M, Doktycz MJ, Pelletier DA. Enrichment of Root Endophytic Bacteria from Populus deltoides and Single-Cell-Genomics Analysis. Appl Environ Microbiol 2016; 82:5698-708. [PMID: 27422831 PMCID: PMC5007785 DOI: 10.1128/aem.01285-16] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 07/07/2016] [Indexed: 12/11/2022] Open
Abstract
UNLABELLED Bacterial endophytes that colonize Populus trees contribute to nutrient acquisition, prime immunity responses, and directly or indirectly increase both above- and below-ground biomasses. Endophytes are embedded within plant material, so physical separation and isolation are difficult tasks. Application of culture-independent methods, such as metagenome or bacterial transcriptome sequencing, has been limited due to the predominance of DNA from the plant biomass. Here, we describe a modified differential and density gradient centrifugation-based protocol for the separation of endophytic bacteria from Populus roots. This protocol achieved substantial reduction in contaminating plant DNA, allowed enrichment of endophytic bacteria away from the plant material, and enabled single-cell genomics analysis. Four single-cell genomes were selected for whole-genome amplification based on their rarity in the microbiome (potentially uncultured taxa) as well as their inferred abilities to form associations with plants. Bioinformatics analyses, including assembly, contamination removal, and completeness estimation, were performed to obtain single-amplified genomes (SAGs) of organisms from the phyla Armatimonadetes, Verrucomicrobia, and Planctomycetes, which were unrepresented in our previous cultivation efforts. Comparative genomic analysis revealed unique characteristics of each SAG that could facilitate future cultivation efforts for these bacteria. IMPORTANCE Plant roots harbor a diverse collection of microbes that live within host tissues. To gain a comprehensive understanding of microbial adaptations to this endophytic lifestyle from strains that cannot be cultivated, it is necessary to separate bacterial cells from the predominance of plant tissue. This study provides a valuable approach for the separation and isolation of endophytic bacteria from plant root tissue. Isolated live bacteria provide material for microbiome sequencing, single-cell genomics, and analyses of genomes of uncultured bacteria to provide genomics information that will facilitate future cultivation attempts.
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Affiliation(s)
- Sagar M Utturkar
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, Tennessee, USA
| | - W Nathan Cude
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Michael S Robeson
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Zamin K Yang
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Dawn M Klingeman
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Miriam L Land
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Steve L Allman
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Tse-Yuan S Lu
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Steven D Brown
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | | | - Mircea Podar
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Mitchel J Doktycz
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Dale A Pelletier
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
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31
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Manga P, Klingeman DM, Lu TYS, Mehlhorn TL, Pelletier DA, Hauser LJ, Wilson CM, Brown SD. Replicates, Read Numbers, and Other Important Experimental Design Considerations for Microbial RNA-seq Identified Using Bacillus thuringiensis Datasets. Front Microbiol 2016; 7:794. [PMID: 27303383 PMCID: PMC4886094 DOI: 10.3389/fmicb.2016.00794] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2016] [Accepted: 05/11/2016] [Indexed: 11/13/2022] Open
Abstract
RNA-seq is being used increasingly for gene expression studies and it is revolutionizing the fields of genomics and transcriptomics. However, the field of RNA-seq analysis is still evolving. Therefore, we specifically designed this study to contain large numbers of reads and four biological replicates per condition so we could alter these parameters and assess their impact on differential expression results. Bacillus thuringiensis strains ATCC10792 and CT43 were grown in two Luria broth medium lots on four dates and transcriptomics data were generated using one lane of sequence output from an Illumina HiSeq2000 instrument for each of the 32 samples, which were then analyzed using DESeq2. Genome coverages across samples ranged from 87 to 465X with medium lots and culture dates identified as major variation sources. Significantly differentially expressed genes (5% FDR, two-fold change) were detected for cultures grown using different medium lots and between different dates. The highly differentially expressed iron acquisition and metabolism genes, were a likely consequence of differing amounts of iron in the two media lots. Indeed, in this study RNA-seq was a tool for predictive biology since we hypothesized and confirmed the two LB medium lots had different iron contents (~two-fold difference). This study shows that the noise in data can be controlled and minimized with appropriate experimental design and by having the appropriate number of replicates and reads for the system being studied. We outline parameters for an efficient and cost effective microbial transcriptomics study.
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Affiliation(s)
- Punita Manga
- Graduate School of Genome Science and Technology, University of TennesseeKnoxville, TN, USA; BioEnergy Science Center, Oak Ridge National LaboratoryOak Ridge, TN, USA
| | - Dawn M Klingeman
- BioEnergy Science Center, Oak Ridge National LaboratoryOak Ridge, TN, USA; Biosciences Division, Oak Ridge National LaboratoryOak Ridge, TN, USA
| | - Tse-Yuan S Lu
- Biosciences Division, Oak Ridge National Laboratory Oak Ridge, TN, USA
| | - Tonia L Mehlhorn
- Environmental Sciences Division, Oak Ridge National Laboratory Oak Ridge, TN, USA
| | - Dale A Pelletier
- Graduate School of Genome Science and Technology, University of TennesseeKnoxville, TN, USA; Biosciences Division, Oak Ridge National LaboratoryOak Ridge, TN, USA
| | - Loren J Hauser
- Graduate School of Genome Science and Technology, University of TennesseeKnoxville, TN, USA; Biosciences Division, Oak Ridge National LaboratoryOak Ridge, TN, USA
| | - Charlotte M Wilson
- BioEnergy Science Center, Oak Ridge National LaboratoryOak Ridge, TN, USA; Biosciences Division, Oak Ridge National LaboratoryOak Ridge, TN, USA
| | - Steven D Brown
- Graduate School of Genome Science and Technology, University of TennesseeKnoxville, TN, USA; BioEnergy Science Center, Oak Ridge National LaboratoryOak Ridge, TN, USA; Biosciences Division, Oak Ridge National LaboratoryOak Ridge, TN, USA
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32
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Xu Q, Resch MG, Podkaminer K, Yang S, Baker JO, Donohoe BS, Wilson C, Klingeman DM, Olson DG, Decker SR, Giannone RJ, Hettich RL, Brown SD, Lynd LR, Bayer EA, Himmel ME, Bomble YJ. Dramatic performance of Clostridium thermocellum explained by its wide range of cellulase modalities. Sci Adv 2016; 2:e1501254. [PMID: 26989779 PMCID: PMC4788478 DOI: 10.1126/sciadv.1501254] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Accepted: 11/30/2015] [Indexed: 05/18/2023]
Abstract
Clostridium thermocellum is the most efficient microorganism for solubilizing lignocellulosic biomass known to date. Its high cellulose digestion capability is attributed to efficient cellulases consisting of both a free-enzyme system and a tethered cellulosomal system wherein carbohydrate active enzymes (CAZymes) are organized by primary and secondary scaffoldin proteins to generate large protein complexes attached to the bacterial cell wall. This study demonstrates that C. thermocellum also uses a type of cellulosomal system not bound to the bacterial cell wall, called the "cell-free" cellulosomal system. The cell-free cellulosome complex can be seen as a "long range cellulosome" because it can diffuse away from the cell and degrade polysaccharide substrates remotely from the bacterial cell. The contribution of these two types of cellulosomal systems in C. thermocellum was elucidated by characterization of mutants with different combinations of scaffoldin gene deletions. The primary scaffoldin, CipA, was found to play the most important role in cellulose degradation by C. thermocellum, whereas the secondary scaffoldins have less important roles. Additionally, the distinct and efficient mode of action of the C. thermocellum exoproteome, wherein the cellulosomes splay or divide biomass particles, changes when either the primary or secondary scaffolds are removed, showing that the intact wild-type cellulosomal system is necessary for this essential mode of action. This new transcriptional and proteomic evidence shows that a functional primary scaffoldin plays a more important role compared to secondary scaffoldins in the proper regulation of CAZyme genes, cellodextrin transport, and other cellular functions.
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Affiliation(s)
- Qi Xu
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401, USA
- BioEnergy Science Center, Oak Ridge, TN 37831, USA
| | - Michael G. Resch
- BioEnergy Science Center, Oak Ridge, TN 37831, USA
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO 80401, USA
| | - Kara Podkaminer
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401, USA
- BioEnergy Science Center, Oak Ridge, TN 37831, USA
| | - Shihui Yang
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO 80401, USA
| | - John O. Baker
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401, USA
- BioEnergy Science Center, Oak Ridge, TN 37831, USA
| | - Bryon S. Donohoe
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401, USA
- BioEnergy Science Center, Oak Ridge, TN 37831, USA
| | - Charlotte Wilson
- BioEnergy Science Center, Oak Ridge, TN 37831, USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Dawn M. Klingeman
- BioEnergy Science Center, Oak Ridge, TN 37831, USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Daniel G. Olson
- BioEnergy Science Center, Oak Ridge, TN 37831, USA
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA
| | - Stephen R. Decker
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401, USA
- BioEnergy Science Center, Oak Ridge, TN 37831, USA
| | - Richard J. Giannone
- BioEnergy Science Center, Oak Ridge, TN 37831, USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Robert L. Hettich
- BioEnergy Science Center, Oak Ridge, TN 37831, USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Steven D. Brown
- BioEnergy Science Center, Oak Ridge, TN 37831, USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Lee R. Lynd
- BioEnergy Science Center, Oak Ridge, TN 37831, USA
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA
| | | | - Michael E. Himmel
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401, USA
- BioEnergy Science Center, Oak Ridge, TN 37831, USA
| | - Yannick J. Bomble
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401, USA
- BioEnergy Science Center, Oak Ridge, TN 37831, USA
- Corresponding author. E-mail:
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33
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Herring CD, Kenealy WR, Joe Shaw A, Covalla SF, Olson DG, Zhang J, Ryan Sillers W, Tsakraklides V, Bardsley JS, Rogers SR, Thorne PG, Johnson JP, Foster A, Shikhare ID, Klingeman DM, Brown SD, Davison BH, Lynd LR, Hogsett DA. Strain and bioprocess improvement of a thermophilic anaerobe for the production of ethanol from wood. Biotechnol Biofuels 2016; 9:125. [PMID: 27313661 PMCID: PMC4910263 DOI: 10.1186/s13068-016-0536-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Accepted: 05/31/2016] [Indexed: 05/16/2023]
Abstract
BACKGROUND The thermophilic, anaerobic bacterium Thermoanaerobacterium saccharolyticum digests hemicellulose and utilizes the major sugars present in biomass. It was previously engineered to produce ethanol at yields equivalent to yeast. While saccharolytic anaerobes have been long studied as potential biomass-fermenting organisms, development efforts for commercial ethanol production have not been reported. RESULTS Here, we describe the highest ethanol titers achieved from T. saccharolyticum during a 4-year project to develop it for industrial production of ethanol from pre-treated hardwood at 51-55 °C. We describe organism and bioprocess development efforts undertaken to improve ethanol production. The final strain M2886 was generated by removing genes for exopolysaccharide synthesis, the regulator perR, and re-introduction of phosphotransacetylase and acetate kinase into the methyglyoxal synthase gene. It was also subject to multiple rounds of adaptation and selection, resulting in mutations later identified by resequencing. The highest ethanol titer achieved was 70 g/L in batch culture with a mixture of cellobiose and maltodextrin. In a "mock hydrolysate" Simultaneous Saccharification and Fermentation (SSF) with Sigmacell-20, glucose, xylose, and acetic acid, an ethanol titer of 61 g/L was achieved, at 92 % of theoretical yield. Fungal cellulases were rapidly inactivated under these conditions and had to be supplemented with cellulosomes from C. thermocellum. Ethanol titers of 31 g/L were reached in a 100 L SSF of pre-treated hardwood and 26 g/L in a fermentation of a hardwood hemicellulose extract. CONCLUSIONS This study demonstrates that thermophilic anaerobes are capable of producing ethanol at high yield and at titers greater than 60 g/L from purified substrates, but additional work is needed to produce the same ethanol titers from pre-treated hardwood.
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Affiliation(s)
- Christopher D. Herring
- />Mascoma Corporation, 67 Etna Rd, Lebanon, NH 03766 USA
- />Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, NH 03755 USA
| | - William R. Kenealy
- />Mascoma Corporation, 67 Etna Rd, Lebanon, NH 03766 USA
- />Verdezyne, Carlsbad, CA USA
| | - A. Joe Shaw
- />Mascoma Corporation, 67 Etna Rd, Lebanon, NH 03766 USA
- />Novogy Inc, Cambridge, MA 02138 USA
| | | | - Daniel G. Olson
- />Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, NH 03755 USA
- />Bioenergy Science Center, Oak Ridge, TN USA
| | - Jiayi Zhang
- />Mascoma Corporation, 67 Etna Rd, Lebanon, NH 03766 USA
- />Genzyme, Cambridge, MA USA
| | - W. Ryan Sillers
- />Mascoma Corporation, 67 Etna Rd, Lebanon, NH 03766 USA
- />Myriant Corporation, Quincy, MA USA
| | - Vasiliki Tsakraklides
- />Mascoma Corporation, 67 Etna Rd, Lebanon, NH 03766 USA
- />Novogy Inc, Cambridge, MA 02138 USA
| | | | | | | | - Jessica P. Johnson
- />Mascoma Corporation, 67 Etna Rd, Lebanon, NH 03766 USA
- />Washington, DC, USA
| | - Abigail Foster
- />Mascoma Corporation, 67 Etna Rd, Lebanon, NH 03766 USA
| | - Indraneel D. Shikhare
- />Mascoma Corporation, 67 Etna Rd, Lebanon, NH 03766 USA
- />Nalco Champion, Houston, TX USA
| | - Dawn M. Klingeman
- />Bioenergy Science Center, Oak Ridge, TN USA
- />Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN USA
| | - Steven D. Brown
- />Bioenergy Science Center, Oak Ridge, TN USA
- />Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN USA
| | - Brian H. Davison
- />Bioenergy Science Center, Oak Ridge, TN USA
- />Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN USA
| | - Lee R. Lynd
- />Mascoma Corporation, 67 Etna Rd, Lebanon, NH 03766 USA
- />Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, NH 03755 USA
- />Bioenergy Science Center, Oak Ridge, TN USA
| | - David A. Hogsett
- />Mascoma Corporation, 67 Etna Rd, Lebanon, NH 03766 USA
- />Novozymes Inc, Davis, CA USA
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Sander K, Wilson CM, Rodriguez M, Klingeman DM, Rydzak T, Davison BH, Brown SD. Clostridium thermocellum DSM 1313 transcriptional responses to redox perturbation. Biotechnol Biofuels 2015; 8:211. [PMID: 26692898 PMCID: PMC4676874 DOI: 10.1186/s13068-015-0394-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 11/24/2015] [Indexed: 05/21/2023]
Abstract
BACKGROUND Clostridium thermocellum is a promising consolidated bioprocessing candidate organism capable of directly converting lignocellulosic biomass to ethanol. Current ethanol yields, productivities, and growth inhibitions are industrial deployment impediments for commodity fuel production by this bacterium. Redox imbalance under certain conditions and in engineered strains may contribute to incomplete substrate utilization and may direct fermentation products to undesirable overflow metabolites. Towards a better understanding of redox metabolism in C. thermocellum, we established continuous growth conditions and analyzed global gene expression during addition of two stress chemicals (methyl viologen and hydrogen peroxide) which changed the fermentation redox potential. RESULTS The addition of methyl viologen to C. thermocellum DSM 1313 chemostat cultures caused an increase in ethanol and lactate yields. A lower fermenter redox potential was observed in response to methyl viologen exposure, which correlated with a decrease in cell yield and significant differential expression of 123 genes (log2 > 1.5 or log2 < -1.5, with a 5 % false discovery rate). Expression levels decreased in four main redox-active systems during methyl viologen exposure; the [NiFe] hydrogenase, sulfate transport and metabolism, ammonia assimilation (GS-GOGAT), and porphyrin/siroheme biosynthesis. Genes encoding sulfate transport and reduction and porphyrin/siroheme biosynthesis are co-located immediately downstream of a putative iscR regulatory gene, which may be a cis-regulatory element controlling expression of these genes. Other genes showing differential expression during methyl viologen exposure included transporters and transposases. CONCLUSIONS The differential expression results from this study support a role for C. thermocellum genes for sulfate transport/reduction, glutamate synthase-glutamine synthetase (the GS-GOGAT system), and porphyrin biosynthesis being involved in redox metabolism and homeostasis. This global profiling study provides gene targets for future studies to elucidate the relative contributions of prospective pathways for co-factor pool re-oxidation and C. thermocellum redox homeostasis.
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Affiliation(s)
- Kyle Sander
- />Bredesen Center for Interdisciplinary Research and Graduate Education, University of Tennessee, Knoxville, TN 37996 USA
- />BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- />Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, TN 37996 USA
| | - Charlotte M. Wilson
- />BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- />Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - Miguel Rodriguez
- />BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- />Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - Dawn M. Klingeman
- />BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- />Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - Thomas Rydzak
- />BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- />Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - Brian H. Davison
- />Bredesen Center for Interdisciplinary Research and Graduate Education, University of Tennessee, Knoxville, TN 37996 USA
- />BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- />Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - Steven D. Brown
- />Bredesen Center for Interdisciplinary Research and Graduate Education, University of Tennessee, Knoxville, TN 37996 USA
- />BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- />Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
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Currie DH, Raman B, Gowen CM, Tschaplinski TJ, Land ML, Brown SD, Covalla SF, Klingeman DM, Yang ZK, Engle NL, Johnson CM, Rodriguez M, Shaw AJ, Kenealy WR, Lynd LR, Fong SS, Mielenz JR, Davison BH, Hogsett DA, Herring CD. Genome-scale resources for Thermoanaerobacterium saccharolyticum. BMC Syst Biol 2015; 9:30. [PMID: 26111937 PMCID: PMC4518999 DOI: 10.1186/s12918-015-0159-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 03/09/2015] [Indexed: 01/12/2023]
Abstract
Background Thermoanaerobacterium saccharolyticum is a hemicellulose-degrading thermophilic anaerobe that was previously engineered to produce ethanol at high yield. A major project was undertaken to develop this organism into an industrial biocatalyst, but the lack of genome information and resources were recognized early on as a key limitation. Results Here we present a set of genome-scale resources to enable the systems level investigation and development of this potentially important industrial organism. Resources include a complete genome sequence for strain JW/SL-YS485, a genome-scale reconstruction of metabolism, tiled microarray data showing transcription units, mRNA expression data from 71 different growth conditions or timepoints and GC/MS-based metabolite analysis data from 42 different conditions or timepoints. Growth conditions include hemicellulose hydrolysate, the inhibitors HMF, furfural, diamide, and ethanol, as well as high levels of cellulose, xylose, cellobiose or maltodextrin. The genome consists of a 2.7 Mbp chromosome and a 110 Kbp megaplasmid. An active prophage was also detected, and the expression levels of CRISPR genes were observed to increase in association with those of the phage. Hemicellulose hydrolysate elicited a response of carbohydrate transport and catabolism genes, as well as poorly characterized genes suggesting a redox challenge. In some conditions, a time series of combined transcription and metabolite measurements were made to allow careful study of microbial physiology under process conditions. As a demonstration of the potential utility of the metabolic reconstruction, the OptKnock algorithm was used to predict a set of gene knockouts that maximize growth-coupled ethanol production. The predictions validated intuitive strain designs and matched previous experimental results. Conclusion These data will be a useful asset for efforts to develop T. saccharolyticum for efficient industrial production of biofuels. The resources presented herein may also be useful on a comparative basis for development of other lignocellulose degrading microbes, such as Clostridium thermocellum. Electronic supplementary material The online version of this article (doi:10.1186/s12918-015-0159-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Devin H Currie
- Mascoma Corporation, 67 Etna Rd, 03766, Lebanon, NH, USA.
| | - Babu Raman
- BioEnergy Science Center, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN, 37831, USA. .,Dow AgroSciences, 9330 Zionsville Road, Indianapolis, IN, 46268, USA.
| | - Christopher M Gowen
- Chemical and Life Science Engineering, Virginia Commonwealth University, P.O. Box 843028, Richmond, Virginia, 23284, USA. .,Centre for Applied Bioscience and Bioengineering, Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Canada.
| | - Timothy J Tschaplinski
- BioEnergy Science Center, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN, 37831, USA.
| | - Miriam L Land
- BioEnergy Science Center, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN, 37831, USA.
| | - Steven D Brown
- BioEnergy Science Center, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN, 37831, USA.
| | - Sean F Covalla
- Mascoma Corporation, 67 Etna Rd, 03766, Lebanon, NH, USA.
| | - Dawn M Klingeman
- BioEnergy Science Center, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN, 37831, USA.
| | - Zamin K Yang
- BioEnergy Science Center, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN, 37831, USA.
| | - Nancy L Engle
- BioEnergy Science Center, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN, 37831, USA.
| | - Courtney M Johnson
- BioEnergy Science Center, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN, 37831, USA.
| | - Miguel Rodriguez
- BioEnergy Science Center, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN, 37831, USA.
| | - A Joe Shaw
- Mascoma Corporation, 67 Etna Rd, 03766, Lebanon, NH, USA. .,Novogy Inc, Cambridge, MA, 02138, USA.
| | | | - Lee R Lynd
- Mascoma Corporation, 67 Etna Rd, 03766, Lebanon, NH, USA. .,Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, NH, 03755, USA.
| | - Stephen S Fong
- Chemical and Life Science Engineering, Virginia Commonwealth University, P.O. Box 843028, Richmond, Virginia, 23284, USA.
| | - Jonathan R Mielenz
- BioEnergy Science Center, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN, 37831, USA.
| | - Brian H Davison
- BioEnergy Science Center, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN, 37831, USA.
| | | | - Christopher D Herring
- Mascoma Corporation, 67 Etna Rd, 03766, Lebanon, NH, USA. .,Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, NH, 03755, USA.
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Utturkar SM, Klingeman DM, Bruno-Barcena JM, Chinn MS, Grunden AM, Köpke M, Brown SD. Sequence data for Clostridium autoethanogenum using three generations of sequencing technologies. Sci Data 2015; 2:150014. [PMID: 25977818 PMCID: PMC4409012 DOI: 10.1038/sdata.2015.14] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Accepted: 03/12/2015] [Indexed: 01/07/2023] Open
Abstract
During the past decade, DNA sequencing output has been mostly dominated by the second generation sequencing platforms which are characterized by low cost, high throughput and shorter read lengths for example, Illumina. The emergence and development of so called third generation sequencing platforms such as PacBio has permitted exceptionally long reads (over 20 kb) to be generated. Due to read length increases, algorithm improvements and hybrid assembly approaches, the concept of one chromosome, one contig and automated finishing of microbial genomes is now a realistic and achievable task for many microbial laboratories. In this paper, we describe high quality sequence datasets which span three generations of sequencing technologies, containing six types of data from four NGS platforms and originating from a single microorganism, Clostridium autoethanogenum. The dataset reported here will be useful for the scientific community to evaluate upcoming NGS platforms, enabling comparison of existing and novel bioinformatics approaches and will encourage interest in the development of innovative experimental and computational methods for NGS data.
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Affiliation(s)
- Sagar M Utturkar
- Graduate School of Genome Science and Technology, University of Tennessee , Knoxville, Tennessee 37919, USA
| | - Dawn M Klingeman
- Biosciences Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, USA
| | - José M Bruno-Barcena
- Department of Plant and Microbial Biology, North Carolina State University , Raleigh, North Carolina 27695, USA
| | - Mari S Chinn
- Department of Biological and Agricultural Engineering, North Carolina State University , Raleigh, North Carolina 27695, USA
| | - Amy M Grunden
- Department of Plant and Microbial Biology, North Carolina State University , Raleigh, North Carolina 27695, USA
| | | | - Steven D Brown
- Graduate School of Genome Science and Technology, University of Tennessee , Knoxville, Tennessee 37919, USA ; Biosciences Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, USA
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Chou WC, Ma Q, Yang S, Cao S, Klingeman DM, Brown SD, Xu Y. Analysis of strand-specific RNA-seq data using machine learning reveals the structures of transcription units in Clostridium thermocellum. Nucleic Acids Res 2015; 43:e67. [PMID: 25765651 PMCID: PMC4446414 DOI: 10.1093/nar/gkv177] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Accepted: 02/22/2015] [Indexed: 12/31/2022] Open
Abstract
Identification of transcription units (TUs) encoded in a bacterial genome is essential to elucidation of transcriptional regulation of the organism. To gain a detailed understanding of the dynamically composed TU structures, we have used four strand-specific RNA-seq (ssRNA-seq) datasets collected under two experimental conditions to derive the genomic TU organization of Clostridium thermocellum using a machine-learning approach. Our method accurately predicted the genomic boundaries of individual TUs based on two sets of parameters measuring the RNA-seq expression patterns across the genome: expression-level continuity and variance. A total of 2590 distinct TUs are predicted based on the four RNA-seq datasets. Among the predicted TUs, 44% have multiple genes. We assessed our prediction method on an independent set of RNA-seq data with longer reads. The evaluation confirmed the high quality of the predicted TUs. Functional enrichment analyses on a selected subset of the predicted TUs revealed interesting biology. To demonstrate the generality of the prediction method, we have also applied the method to RNA-seq data collected on Escherichia coli and achieved high prediction accuracies. The TU prediction program named SeqTU is publicly available at https://code.google.com/p/seqtu/. We expect that the predicted TUs can serve as the baseline information for studying transcriptional and post-transcriptional regulation in C. thermocellum and other bacteria.
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Affiliation(s)
- Wen-Chi Chou
- Computational Systems Biology Lab, Department of Biochemistry and Molecular Biology, and Institute of Bioinformatics, University of Georgia, GA 30602, USA BioEnergy Science Center, TN 37831, USA
| | - Qin Ma
- Computational Systems Biology Lab, Department of Biochemistry and Molecular Biology, and Institute of Bioinformatics, University of Georgia, GA 30602, USA BioEnergy Science Center, TN 37831, USA
| | - Shihui Yang
- BioEnergy Science Center, TN 37831, USA Biosciences Division, Oak Ridge National Laboratory, TN 37831, USA National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO 80401, USA
| | - Sha Cao
- Computational Systems Biology Lab, Department of Biochemistry and Molecular Biology, and Institute of Bioinformatics, University of Georgia, GA 30602, USA
| | - Dawn M Klingeman
- BioEnergy Science Center, TN 37831, USA Biosciences Division, Oak Ridge National Laboratory, TN 37831, USA
| | - Steven D Brown
- BioEnergy Science Center, TN 37831, USA Biosciences Division, Oak Ridge National Laboratory, TN 37831, USA
| | - Ying Xu
- Computational Systems Biology Lab, Department of Biochemistry and Molecular Biology, and Institute of Bioinformatics, University of Georgia, GA 30602, USA BioEnergy Science Center, TN 37831, USA College of Computer Science and Technology and School of Public Health, Jilin University, Changchun, Jilin 130012, China
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Utturkar SM, Klingeman DM, Land ML, Schadt CW, Doktycz MJ, Pelletier DA, Brown SD. Evaluation and validation of de novo and hybrid assembly techniques to derive high-quality genome sequences. ACTA ACUST UNITED AC 2014; 30:2709-16. [PMID: 24930142 PMCID: PMC4173024 DOI: 10.1093/bioinformatics/btu391] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
MOTIVATION To assess the potential of different types of sequence data combined with de novo and hybrid assembly approaches to improve existing draft genome sequences. RESULTS Illumina, 454 and PacBio sequencing technologies were used to generate de novo and hybrid genome assemblies for four different bacteria, which were assessed for quality using summary statistics (e.g. number of contigs, N50) and in silico evaluation tools. Differences in predictions of multiple copies of rDNA operons for each respective bacterium were evaluated by PCR and Sanger sequencing, and then the validated results were applied as an additional criterion to rank assemblies. In general, assemblies using longer PacBio reads were better able to resolve repetitive regions. In this study, the combination of Illumina and PacBio sequence data assembled through the ALLPATHS-LG algorithm gave the best summary statistics and most accurate rDNA operon number predictions. This study will aid others looking to improve existing draft genome assemblies. AVAILABILITY AND IMPLEMENTATION All assembly tools except CLC Genomics Workbench are freely available under GNU General Public License. CONTACT brownsd@ornl.gov SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Sagar M Utturkar
- Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, TN 37919, USA and Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Dawn M Klingeman
- Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, TN 37919, USA and Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Miriam L Land
- Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, TN 37919, USA and Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Christopher W Schadt
- Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, TN 37919, USA and Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, TN 37919, USA and Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Mitchel J Doktycz
- Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, TN 37919, USA and Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, TN 37919, USA and Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Dale A Pelletier
- Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, TN 37919, USA and Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, TN 37919, USA and Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Steven D Brown
- Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, TN 37919, USA and Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, TN 37919, USA and Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
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Wilson CM, Rodriguez M, Johnson CM, Martin SL, Chu TM, Wolfinger RD, Hauser LJ, Land ML, Klingeman DM, Syed MH, Ragauskas AJ, Tschaplinski TJ, Mielenz JR, Brown SD. Global transcriptome analysis of Clostridium thermocellum ATCC 27405 during growth on dilute acid pretreated Populus and switchgrass. Biotechnol Biofuels 2013; 6:179. [PMID: 24295562 PMCID: PMC3880215 DOI: 10.1186/1754-6834-6-179] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Accepted: 11/19/2013] [Indexed: 05/04/2023]
Abstract
BACKGROUND The thermophilic anaerobe Clostridium thermocellum is a candidate consolidated bioprocessing (CBP) biocatalyst for cellulosic ethanol production. The aim of this study was to investigate C. thermocellum genes required to ferment biomass substrates and to conduct a robust comparison of DNA microarray and RNA sequencing (RNA-seq) analytical platforms. RESULTS C. thermocellum ATCC 27405 fermentations were conducted with a 5 g/L solid substrate loading of either pretreated switchgrass or Populus. Quantitative saccharification and inductively coupled plasma emission spectroscopy (ICP-ES) for elemental analysis revealed composition differences between biomass substrates, which may have influenced growth and transcriptomic profiles. High quality RNA was prepared for C. thermocellum grown on solid substrates and transcriptome profiles were obtained for two time points during active growth (12 hours and 37 hours postinoculation). A comparison of two transcriptomic analytical techniques, microarray and RNA-seq, was performed and the data analyzed for statistical significance. Large expression differences for cellulosomal genes were not observed. We updated gene predictions for the strain and a small novel gene, Cthe_3383, with a putative AgrD peptide quorum sensing function was among the most highly expressed genes. RNA-seq data also supported different small regulatory RNA predictions over others. The DNA microarray gave a greater number (2,351) of significant genes relative to RNA-seq (280 genes when normalized by the kernel density mean of M component (KDMM) method) in an analysis of variance (ANOVA) testing method with a 5% false discovery rate (FDR). When a 2-fold difference in expression threshold was applied, 73 genes were significantly differentially expressed in common between the two techniques. Sulfate and phosphate uptake/utilization genes, along with genes for a putative efflux pump system were some of the most differentially regulated transcripts when profiles for C. thermocellum grown on either pretreated switchgrass or Populus were compared. CONCLUSIONS Our results suggest that a high degree of agreement in differential gene expression measurements between transcriptomic platforms is possible, but choosing an appropriate normalization regime is essential.
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Affiliation(s)
- Charlotte M Wilson
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Miguel Rodriguez
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Courtney M Johnson
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | | | | | | | - Loren J Hauser
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Miriam L Land
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Dawn M Klingeman
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Mustafa H Syed
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Arthur J Ragauskas
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Timothy J Tschaplinski
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Jonathan R Mielenz
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Steven D Brown
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
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Brown SD, Guss AM, Karpinets TV, Parks JM, Smolin N, Yang S, Land ML, Klingeman DM, Bhandiwad A, Rodriguez M, Raman B, Shao X, Mielenz JR, Smith JC, Keller M, Lynd LR. Mutant alcohol dehydrogenase leads to improved ethanol tolerance in Clostridium thermocellum. Proc Natl Acad Sci U S A 2011; 108:13752-7. [PMID: 21825121 PMCID: PMC3158198 DOI: 10.1073/pnas.1102444108] [Citation(s) in RCA: 141] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Clostridium thermocellum is a thermophilic, obligately anaerobic, gram-positive bacterium that is a candidate microorganism for converting cellulosic biomass into ethanol through consolidated bioprocessing. Ethanol intolerance is an important metric in terms of process economics, and tolerance has often been described as a complex and likely multigenic trait for which complex gene interactions come into play. Here, we resequence the genome of an ethanol-tolerant mutant, show that the tolerant phenotype is primarily due to a mutated bifunctional acetaldehyde-CoA/alcohol dehydrogenase gene (adhE), hypothesize based on structural analysis that cofactor specificity may be affected, and confirm this hypothesis using enzyme assays. Biochemical assays confirm a complete loss of NADH-dependent activity with concomitant acquisition of NADPH-dependent activity, which likely affects electron flow in the mutant. The simplicity of the genetic basis for the ethanol-tolerant phenotype observed here informs rational engineering of mutant microbial strains for cellulosic ethanol production.
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Affiliation(s)
- Steven D Brown
- Biosciences Division and BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
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Gao H, Pattison D, Yan T, Klingeman DM, Wang X, Petrosino J, Hemphill L, Wan X, Leaphart AB, Weinstock GM, Palzkill T, Zhou J. Generation and validation of a Shewanella oneidensis MR-1 clone set for protein expression and phage display. PLoS One 2008; 3:e2983. [PMID: 18714347 PMCID: PMC2500165 DOI: 10.1371/journal.pone.0002983] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2008] [Accepted: 07/28/2008] [Indexed: 12/02/2022] Open
Abstract
A comprehensive gene collection for S. oneidensis was constructed using the lambda recombinase (Gateway) cloning system. A total of 3584 individual ORFs (85%) have been successfully cloned into the entry plasmids. To validate the use of the clone set, three sets of ORFs were examined within three different destination vectors constructed in this study. Success rates for heterologous protein expression of S. oneidensis His- or His/GST- tagged proteins in E. coli were approximately 70%. The ArcA and NarP transcription factor proteins were tested in an in vitro binding assay to demonstrate that functional proteins can be successfully produced using the clone set. Further functional validation of the clone set was obtained from phage display experiments in which a phage encoding thioredoxin was successfully isolated from a pool of 80 different clones after three rounds of biopanning using immobilized anti-thioredoxin antibody as a target. This clone set complements existing genomic (e.g., whole-genome microarray) and other proteomic tools (e.g., mass spectrometry-based proteomic analysis), and facilitates a wide variety of integrated studies, including protein expression, purification, and functional analyses of proteins both in vivo and in vitro.
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Affiliation(s)
- Haichun Gao
- Institute for Environmental Genomics, University of Oklahoma, Norman, Oklahoma, United States of America
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
| | - Donna Pattison
- Baylor College of Medicine, Houston, Texas, United States of America
| | - Tingfen Yan
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
| | - Dawn M. Klingeman
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
| | - Xiaohu Wang
- Baylor College of Medicine, Houston, Texas, United States of America
| | - Joseph Petrosino
- Baylor College of Medicine, Houston, Texas, United States of America
| | - Lisa Hemphill
- Baylor College of Medicine, Houston, Texas, United States of America
| | - Xiufeng Wan
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
| | - Adam B. Leaphart
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
| | | | - Timothy Palzkill
- Baylor College of Medicine, Houston, Texas, United States of America
- * E-mail: (TP); (JZ)
| | - Jizhong Zhou
- Institute for Environmental Genomics, University of Oklahoma, Norman, Oklahoma, United States of America
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
- * E-mail: (TP); (JZ)
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Gao W, Liu Y, Giometti CS, Tollaksen SL, Khare T, Wu L, Klingeman DM, Fields MW, Zhou J. Knock-out of SO1377 gene, which encodes the member of a conserved hypothetical bacterial protein family COG2268, results in alteration of iron metabolism, increased spontaneous mutation and hydrogen peroxide sensitivity in Shewanella oneidensis MR-1. BMC Genomics 2006; 7:76. [PMID: 16600046 PMCID: PMC1468410 DOI: 10.1186/1471-2164-7-76] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2006] [Accepted: 04/06/2006] [Indexed: 01/28/2023] Open
Abstract
Background Shewanella oneidensis MR-1 is a facultative, gram-negative bacterium capable of coupling the oxidation of organic carbon to a wide range of electron acceptors such as oxygen, nitrate and metals, and has potential for bioremediation of heavy metal contaminated sites. The complete 5-Mb genome of S. oneidensis MR-1 was sequenced and standard sequence-comparison methods revealed approximately 42% of the MR-1 genome encodes proteins of unknown function. Defining the functions of hypothetical proteins is a great challenge and may need a systems approach. In this study, by using integrated approaches including whole genomic microarray and proteomics, we examined knockout effects of the gene encoding SO1377 (gi24372955), a member of the conserved, hypothetical, bacterial protein family COG2268 (Clusters of Orthologous Group) in bacterium Shewanella oneidensis MR-1, under various physiological conditions. Results Compared with the wild-type strain, growth assays showed that the deletion mutant had a decreased growth rate when cultured aerobically, but not affected under anaerobic conditions. Whole-genome expression (RNA and protein) profiles revealed numerous gene and protein expression changes relative to the wild-type control, including some involved in iron metabolism, oxidative damage protection and respiratory electron transfer, e. g. complex IV of the respiration chain. Although total intracellular iron levels remained unchanged, whole-cell electron paramagnetic resonance (EPR) demonstrated that the level of free iron in mutant cells was 3 times less than that of the wild-type strain. Siderophore excretion in the mutant also decreased in iron-depleted medium. The mutant was more sensitive to hydrogen peroxide and gave rise to 100 times more colonies resistant to gentamicin or kanamycin. Conclusion Our results showed that the knock-out of SO1377 gene had pleiotropic effects and suggested that SO1377 may play a role in iron homeostasis and oxidative damage protection in S. oneidensis MR-1.
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Affiliation(s)
- Weimin Gao
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Yongqing Liu
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Carol S Giometti
- Biosciences Division, Argonne National Laboratory, Argonne, IL 60439, USA
| | - Sandra L Tollaksen
- Biosciences Division, Argonne National Laboratory, Argonne, IL 60439, USA
| | - Tripti Khare
- Biosciences Division, Argonne National Laboratory, Argonne, IL 60439, USA
| | - Liyou Wu
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Dawn M Klingeman
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Matthew W Fields
- Department of Microbiology, Miami University, Oxford, OH 45056, USA
| | - Jizhong Zhou
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- Institute for Environmental Genomics and Department of Botany and Microbiology, University of Oklahoma, Norman, OK 73019, USA
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43
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Beliaev AS, Klingeman DM, Klappenbach JA, Wu L, Romine MF, Tiedje JM, Nealson KH, Fredrickson JK, Zhou J. Global transcriptome analysis of Shewanella oneidensis MR-1 exposed to different terminal electron acceptors. J Bacteriol 2005; 187:7138-45. [PMID: 16199584 PMCID: PMC1251602 DOI: 10.1128/jb.187.20.7138-7145.2005] [Citation(s) in RCA: 186] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
To gain insight into the complex structure of the energy-generating networks in the dissimilatory metal reducer Shewanella oneidensis MR-1, global mRNA patterns were examined in cells exposed to a wide range of metal and non-metal electron acceptors. Gene expression patterns were similar irrespective of which metal ion was used as electron acceptor, with 60% of the differentially expressed genes showing similar induction or repression relative to fumarate-respiring conditions. Several groups of genes exhibited elevated expression levels in the presence of metals, including those encoding putative multidrug efflux transporters, detoxification proteins, extracytoplasmic sigma factors and PAS-domain regulators. Only one of the 42 predicted c-type cytochromes in MR-1, SO3300, displayed significantly elevated transcript levels across all metal-reducing conditions. Genes encoding decaheme cytochromes MtrC and MtrA that were previously linked to the reduction of different forms of Fe(III) and Mn(IV), exhibited only slight decreases in relative mRNA abundances under metal-reducing conditions. In contrast, specific transcriptome responses were displayed to individual non-metal electron acceptors resulting in the identification of unique groups of nitrate-, thiosulfate- and TMAO-induced genes including previously uncharacterized multi-cytochrome gene clusters. Collectively, the gene expression results reflect the fundamental differences between metal and non-metal respiratory pathways of S. oneidensis MR-1, where the coordinate induction of detoxification and stress response genes play a key role in adaptation of this organism under metal-reducing conditions. Moreover, the relative paucity and/or the constitutive nature of genes involved in electron transfer to metals is likely due to the low-specificity and the opportunistic nature of the metal-reducing electron transport pathways.
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Affiliation(s)
- A S Beliaev
- Biological Sciences Division, Pacific Northwest National Laboratory, P.O. Box 999, MS P7-50, Richland, Washington 99352, USA.
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