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Voutsinos MY, West-Roberts JA, Sachdeva R, Moreau JW, Banfield JF. Weathered granites and soils harbour microbes with lanthanide-dependent methylotrophic enzymes. BMC Biol 2024; 22:41. [PMID: 38369453 PMCID: PMC10875860 DOI: 10.1186/s12915-024-01841-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 02/07/2024] [Indexed: 02/20/2024] Open
Abstract
BACKGROUND Prior to soil formation, phosphate liberated by rock weathering is often sequestered into highly insoluble lanthanide phosphate minerals. Dissolution of these minerals releases phosphate and lanthanides to the biosphere. Currently, the microorganisms involved in phosphate mineral dissolution and the role of lanthanides in microbial metabolism are poorly understood. RESULTS Although there have been many studies of soil microbiology, very little research has investigated microbiomes of weathered rock. Here, we sampled weathered granite and associated soil to identify the zones of lanthanide phosphate mineral solubilisation and genomically define the organisms implicated in lanthanide utilisation. We reconstructed 136 genomes from 11 bacterial phyla and found that gene clusters implicated in lanthanide-based metabolism of methanol (primarily xoxF3 and xoxF5) are surprisingly common in microbial communities in moderately weathered granite. Notably, xoxF3 systems were found in Verrucomicrobia for the first time, and in Acidobacteria, Gemmatimonadetes and Alphaproteobacteria. The xoxF-containing gene clusters are shared by diverse Acidobacteria and Gemmatimonadetes, and include conserved hypothetical proteins and transporters not associated with the few well studied xoxF systems. Given that siderophore-like molecules that strongly bind lanthanides may be required to solubilise lanthanide phosphates, it is notable that candidate metallophore biosynthesis systems were most prevalent in bacteria in moderately weathered rock, especially in Acidobacteria with lanthanide-based systems. CONCLUSIONS Phosphate mineral dissolution, putative metallophore production and lanthanide utilisation by enzymes involved in methanol oxidation linked to carbonic acid production co-occur in the zone of moderate granite weathering. In combination, these microbial processes likely accelerate the conversion of granitic rock to soil.
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Affiliation(s)
- Marcos Y Voutsinos
- School of Geography, Earth and Atmospheric Sciences, The University of Melbourne, Melbourne, VIC, Australia
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Melbourne, Australia
| | - Jacob A West-Roberts
- Department of Environmental Science, Policy and Management, University of California, Berkeley, CA, USA
| | - Rohan Sachdeva
- Department of Earth and Planetary Science, University of California, Berkeley, CA, USA
| | - John W Moreau
- School of Geographical and Earth Sciences, University of Glasgow, Glasgow, UK
| | - Jillian F Banfield
- School of Geography, Earth and Atmospheric Sciences, The University of Melbourne, Melbourne, VIC, Australia.
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Melbourne, Australia.
- Department of Environmental Science, Policy and Management, University of California, Berkeley, CA, USA.
- Department of Earth and Planetary Science, University of California, Berkeley, CA, USA.
- Innovative Genomics Institute, University of California Berkeley, Berkeley, CA, USA.
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Gorniak L, Bechwar J, Westermann M, Steiniger F, Wegner CE. Different lanthanide elements induce strong gene expression changes in a lanthanide-accumulating methylotroph. Microbiol Spectr 2023; 11:e0086723. [PMID: 37909735 PMCID: PMC10848612 DOI: 10.1128/spectrum.00867-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Accepted: 09/25/2023] [Indexed: 11/03/2023] Open
Abstract
IMPORTANCE Since its discovery, Ln-dependent metabolism in bacteria attracted a lot of attention due to its bio-metallurgical application potential regarding Ln recycling and circular economy. The physiological role of Ln is mostly studied dependent on presence and absence. Comparisons of how different (utilizable) Ln affect metabolism have rarely been done. We noticed unexpectedly pronounced changes in gene expression caused by different Ln supplementation. Our research suggests that strain RH AL1 distinguishes different Ln elements and that the effect of Ln reaches into many aspects of metabolism, for instance, chemotaxis, motility, and polyhydroxyalkanoate metabolism. Our findings regarding Ln accumulation suggest a distinction between individual Ln elements and provide insights relating to intracellular Ln homeostasis. Understanding comprehensively how microbes distinguish and handle different Ln elements is key for turning knowledge into application regarding Ln-centered biometallurgy.
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Affiliation(s)
- Linda Gorniak
- Institute of Biodiversity, Aquatic Geomicrobiology, Friedrich Schiller University, Jena, Germany
| | - Julia Bechwar
- Institute of Biodiversity, Aquatic Geomicrobiology, Friedrich Schiller University, Jena, Germany
| | | | - Frank Steiniger
- Electron Microscopy Center, Jena University Hospital, Jena, Germany
| | - Carl-Eric Wegner
- Institute of Biodiversity, Aquatic Geomicrobiology, Friedrich Schiller University, Jena, Germany
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Hobart KK, Greensky Z, Hernandez K, Feinberg JM, Bailey JV, Jones DS. Microbial communities from weathered outcrops of a sulfide-rich ultramafic intrusion, and implications for mine waste management. Environ Microbiol 2023; 25:3512-3526. [PMID: 37667903 DOI: 10.1111/1462-2920.16489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 07/20/2023] [Indexed: 09/06/2023]
Abstract
The Duluth Complex (DC) contains sulfide-rich magmatic intrusions that represent one of the largest known economic deposits of copper, nickel, and platinum group elements. Previous work showed that microbial communities associated with experimentally-weathered DC waste rock and tailings were dominated by uncultivated taxa and organisms not typically associated with mine waste. However, those experiments were designed for kinetic testing and do not necessarily represent the conditions expected for long-term environmental weathering. We used 16S rRNA gene methods to characterize the microbial communities present on the surfaces of naturally-weathered and historically disturbed outcrops of DC material. Rock surfaces were dominated by diverse uncultured Ktedonobacteria, Acetobacteria, and Actinobacteria, with abundant algae and other phototrophs. These communities were distinct from microbial assemblages from experimentally-weathered DC rocks, suggesting different energy and nutrient resources in environmental samples. Sulfide mineral incubations performed with and without algae showed that photosynthetic microorganisms could have an inhibitory effect on autotrophic populations, resulting in slightly lower sulfate release and differences in dominant microorganisms. The microbial assemblages from these weathered outcrops show how communities develop during weathering of sulfide-rich DC rocks and represent baseline data that could evaluate the effectiveness of future reclamation of waste produced by large-scale mining operations.
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Affiliation(s)
- Kathryn K Hobart
- Department of Earth & Environmental Sciences, University of Minnesota, Minneapolis, Minnesota, USA
- Institute for Rock Magnetism, University of Minnesota, Minneapolis, Minnesota, USA
| | - ZhaaZhaawaanong Greensky
- Department of Earth & Environmental Sciences, University of Minnesota, Minneapolis, Minnesota, USA
| | - Kimberly Hernandez
- Department of Earth & Environmental Sciences, University of Minnesota, Minneapolis, Minnesota, USA
| | - Joshua M Feinberg
- Department of Earth & Environmental Sciences, University of Minnesota, Minneapolis, Minnesota, USA
- Institute for Rock Magnetism, University of Minnesota, Minneapolis, Minnesota, USA
| | - Jake V Bailey
- Department of Earth & Environmental Sciences, University of Minnesota, Minneapolis, Minnesota, USA
| | - Daniel S Jones
- Department of Earth & Environmental Sciences, University of Minnesota, Minneapolis, Minnesota, USA
- Department of Earth and Environmental Science, New Mexico Institute of Mining and Technology, Socorro, New Mexico, USA
- National Cave and Karst Research Institute, Carlsbad, New Mexico, USA
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4
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Mara P, Geller-McGrath D, Edgcomb V, Beaudoin D, Morono Y, Teske A. Metagenomic profiles of archaea and bacteria within thermal and geochemical gradients of the Guaymas Basin deep subsurface. Nat Commun 2023; 14:7768. [PMID: 38012208 PMCID: PMC10681998 DOI: 10.1038/s41467-023-43296-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 11/02/2023] [Indexed: 11/29/2023] Open
Abstract
Previous studies of microbial communities in subseafloor sediments reported that microbial abundance and diversity decrease with sediment depth and age, and microbes dominating at depth tend to be a subset of the local seafloor community. However, the existence of geographically widespread, subsurface-adapted specialists is also possible. Here, we use metagenomic and metatranscriptomic analyses of the hydrothermally heated, sediment layers of Guaymas Basin (Gulf of California, Mexico) to examine the distribution and activity patterns of bacteria and archaea along thermal, geochemical and cell count gradients. We find that the composition and distribution of metagenome-assembled genomes (MAGs), dominated by numerous lineages of Chloroflexota and Thermoproteota, correlate with biogeochemical parameters as long as temperatures remain moderate, but downcore increasing temperatures beyond ca. 45 ºC override other factors. Consistently, MAG size and diversity decrease with increasing temperature, indicating a downcore winnowing of the subsurface biosphere. By contrast, specific archaeal MAGs within the Thermoproteota and Hadarchaeota increase in relative abundance and in recruitment of transcriptome reads towards deeper, hotter sediments, marking the transition towards a specialized deep, hot biosphere.
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Affiliation(s)
- Paraskevi Mara
- Geology and Geophysics Department, Woods Hole Oceanographic Institution, Woods Hole, MA, 02543, USA
| | - David Geller-McGrath
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA, 02543, USA
| | - Virginia Edgcomb
- Geology and Geophysics Department, Woods Hole Oceanographic Institution, Woods Hole, MA, 02543, USA
| | - David Beaudoin
- Geology and Geophysics Department, Woods Hole Oceanographic Institution, Woods Hole, MA, 02543, USA
| | - Yuki Morono
- Kochi Institute for Core Sample Research, Institute for Extra-cutting-edge Science and Technology Avantgarde Research (X-STAR), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Monobe, Nankoku, Kochi, Japan
| | - Andreas Teske
- Department of Earth, Marine and Environmental Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
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Albright S, Louca S. Trait biases in microbial reference genomes. Sci Data 2023; 10:84. [PMID: 36759614 PMCID: PMC9911409 DOI: 10.1038/s41597-023-01994-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Accepted: 01/31/2023] [Indexed: 02/11/2023] Open
Abstract
Common culturing techniques and priorities bias our discovery towards specific traits that may not be representative of microbial diversity in nature. So far, these biases have not been systematically examined. To address this gap, here we use 116,884 publicly available metagenome-assembled genomes (MAGs, completeness ≥80%) from 203 surveys worldwide as a culture-independent sample of bacterial and archaeal diversity, and compare these MAGs to the popular RefSeq genome database, which heavily relies on cultures. We compare the distribution of 12,454 KEGG gene orthologs (used as trait proxies) in the MAGs and RefSeq genomes, while controlling for environment type (ocean, soil, lake, bioreactor, human, and other animals). Using statistical modeling, we then determine the conditional probabilities that a species is represented in RefSeq depending on its genetic repertoire. We find that the majority of examined genes are significantly biased for or against in RefSeq. Our systematic estimates of gene prevalences across bacteria and archaea in nature and gene-specific biases in reference genomes constitutes a resource for addressing these issues in the future.
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Affiliation(s)
- Sage Albright
- Department of Biology, University of Oregon, Eugene, USA
| | - Stilianos Louca
- Department of Biology, University of Oregon, Eugene, USA. .,Institute of Ecology and Evolution, University of Oregon, Eugene, USA.
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Quantitative Stable-Isotope Probing (qSIP) with Metagenomics Links Microbial Physiology and Activity to Soil Moisture in Mediterranean-Climate Grassland Ecosystems. mSystems 2022; 7:e0041722. [PMID: 36300946 PMCID: PMC9765451 DOI: 10.1128/msystems.00417-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The growth and physiology of soil microorganisms, which play vital roles in biogeochemical cycling, are shaped by both current and historical soil environmental conditions. Here, we developed and applied a genome-resolved metagenomic implementation of quantitative stable isotope probing (qSIP) with an H218O labeling experiment to identify actively growing soil microorganisms and their genomic capacities. qSIP enabled measurement of taxon-specific growth because isotopic incorporation into microbial DNA requires production of new genome copies. We studied three Mediterranean grassland soils across a rainfall gradient to evaluate the hypothesis that historic precipitation levels are an important factor controlling trait selection. We used qSIP-informed genome-resolved metagenomics to resolve the active subset of soil community members and identify their characteristic ecophysiological traits. Higher year-round precipitation levels correlated with higher activity and growth rates of flagellar motile microorganisms. In addition to heavily isotopically labeled bacteria, we identified abundant isotope-labeled phages, suggesting phage-induced cell lysis likely contributed to necromass production at all three sites. Further, there was a positive correlation between phage activity and the activity of putative phage hosts. Contrary to our expectations, the capacity to decompose the diverse complex carbohydrates common in soil organic matter or oxidize methanol and carbon monoxide were broadly distributed across active and inactive bacteria in all three soils, implying that these traits are not highly selected for by historical precipitation. IMPORTANCE Soil moisture is a critical factor that strongly shapes the lifestyle of soil organisms by changing access to nutrients, controlling oxygen diffusion, and regulating the potential for mobility. We identified active microorganisms in three grassland soils with similar mineral contexts, yet different historic rainfall inputs, by adding water labeled with a stable isotope and tracking that isotope in DNA of growing microbes. By examining the genomes of active and inactive microorganisms, we identified functions that are enriched in growing organisms, and showed that different functions were selected for in different soils. Wetter soil had higher activity of motile organisms, but activity of pathways for degradation of soil organic carbon compounds, including simple carbon substrates, were comparable for all three soils. We identified many labeled, and thus active bacteriophages (viruses that infect bacteria), implying that the cells they killed contributed to soil organic matter. The activity of these bacteriophages was significantly correlated with activity of their hosts.
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Wang S, Feng S, Pan C, Guo X. FineFDR: Fine-grained Taxonomy-specific False Discovery Rates Control in Metaproteomics. PROCEEDINGS. IEEE INTERNATIONAL CONFERENCE ON BIOINFORMATICS AND BIOMEDICINE 2022; 2022:287-292. [PMID: 36910011 PMCID: PMC9998077 DOI: 10.1109/bibm55620.2022.9995401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Microbial community proteomics, also termed metaproteomics, investigates all proteins expressed by a microbiota. Tandem mass spectrometry (MS/MS) is the typical method for identifying proteins in metaproteomics, which involves searching the mass spectra against a protein sequence database. A major post-analysis step is controlling the false discovery rate (FDR), i.e., the ratio of false positives to the total number of annotations. The current popular target-decoy FDR estimation method treats all the peptides and proteins equally and overlooks that they could have varied probabilities of being identified. In this study, we report FineFDR, a framework for FDR assessment at fine-grained levels with taxonomy information considered. FineFDR groups the identified peptide-spectrum matches, peptides, and proteins from different taxonomic units and estimates the FDR in each group separately. Empirical experiments on the simulated and real-world data sets demonstrate that our FineFDR achieved higher precision and more peptide and protein identifications when compared to the state-of-the-art methods, such as Comet, Percolator, TIDD, and Tailor. FineFDR is freely available under the GNU GPL license at https://github.com/Biocomputing-Research-Group/FDR.
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Affiliation(s)
- Shengze Wang
- Department of Computer Science and Engineering University of North Texas, Denton, TX 76207, United States
| | - Shichao Feng
- Department of Computer Science and Engineering University of North Texas, Denton, TX 76207, United States
| | - Chongle Pan
- School of Computer Science Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK 73019, United States
| | - Xuan Guo
- Department of Computer Science and Engineering University of North Texas, Denton, TX 76207, United States
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Feng S, Ji HL, Wang H, Zhang B, Sterzenbach R, Pan C, Guo X. MetaLP: An integrative linear programming method for protein inference in metaproteomics. PLoS Comput Biol 2022; 18:e1010603. [PMID: 36269761 PMCID: PMC9629623 DOI: 10.1371/journal.pcbi.1010603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 11/02/2022] [Accepted: 09/26/2022] [Indexed: 11/07/2022] Open
Abstract
Metaproteomics based on high-throughput tandem mass spectrometry (MS/MS) plays a crucial role in characterizing microbiome functions. The acquired MS/MS data is searched against a protein sequence database to identify peptides, which are then used to infer a list of proteins present in a metaproteome sample. While the problem of protein inference has been well-studied for proteomics of single organisms, it remains a major challenge for metaproteomics of complex microbial communities because of the large number of degenerate peptides shared among homologous proteins in different organisms. This challenge calls for improved discrimination of true protein identifications from false protein identifications given a set of unique and degenerate peptides identified in metaproteomics. MetaLP was developed here for protein inference in metaproteomics using an integrative linear programming method. Taxonomic abundance information extracted from metagenomics shotgun sequencing or 16s rRNA gene amplicon sequencing, was incorporated as prior information in MetaLP. Benchmarking with mock, human gut, soil, and marine microbial communities demonstrated significantly higher numbers of protein identifications by MetaLP than ProteinLP, PeptideProphet, DeepPep, PIPQ, and Sipros Ensemble. In conclusion, MetaLP could substantially improve protein inference for complex metaproteomes by incorporating taxonomic abundance information in a linear programming model.
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Affiliation(s)
- Shichao Feng
- Department of Computer Science and Engineering, University of North Texas, Denton, Texas, United States of America
| | - Hong-Long Ji
- Department of Cellular and Molecular Biology, University of Texas at Tyler, Tyler, Texas, United States of America
- Texas Lung Injury Institute, University of Texas at Tyler, Tyler, Texas, United States of America
| | - Huan Wang
- College of Informatics, Huazhong Agricultural University, Wuhan, Hubei, CHINA
| | - Bailu Zhang
- Department of Computer Science and Engineering, University of North Texas, Denton, Texas, United States of America
| | - Ryan Sterzenbach
- Department of Computer Science and Engineering, University of North Texas, Denton, Texas, United States of America
- Department of Biomedical Engineering, University of North Texas, Denton, Texas, United States of America
| | - Chongle Pan
- School of Computer Science, University of Oklahoma, Norman, Oklahoma, United States of America
| | - Xuan Guo
- Department of Computer Science and Engineering, University of North Texas, Denton, Texas, United States of America
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Kanukollu S, Remus R, Rücker AM, Buchen-Tschiskale C, Hoffmann M, Kolb S. Methanol utilizers of the rhizosphere and phyllosphere of a common grass and forb host species. ENVIRONMENTAL MICROBIOME 2022; 17:35. [PMID: 35794633 PMCID: PMC9258066 DOI: 10.1186/s40793-022-00428-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 06/14/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND Managed grasslands are global sources of atmospheric methanol, which is one of the most abundant volatile organic compounds in the atmosphere and promotes oxidative capacity for tropospheric and stratospheric ozone depletion. The phyllosphere is a favoured habitat of plant-colonizing methanol-utilizing bacteria. These bacteria also occur in the rhizosphere, but their relevance for methanol consumption and ecosystem fluxes is unclear. Methanol utilizers of the plant-associated microbiota are key for the mitigation of methanol emission through consumption. However, information about grassland plant microbiota members, their biodiversity and metabolic traits, and thus key actors in the global methanol budget is largely lacking. RESULTS We investigated the methanol utilization and consumption potentials of two common plant species (Festuca arundinacea and Taraxacum officinale) in a temperate grassland. The selected grassland exhibited methanol formation. The detection of 13C derived from 13C-methanol in 16S rRNA of the plant microbiota by stable isotope probing (SIP) revealed distinct methanol utilizer communities in the phyllosphere, roots and rhizosphere but not between plant host species. The phyllosphere was colonized by members of Gamma- and Betaproteobacteria. In the rhizosphere, 13C-labelled Bacteria were affiliated with Deltaproteobacteria, Gemmatimonadates, and Verrucomicrobiae. Less-abundant 13C-labelled Bacteria were affiliated with well-known methylotrophs of Alpha-, Gamma-, and Betaproteobacteria. Additional metagenome analyses of both plants were consistent with the SIP results and revealed Bacteria with methanol dehydrogenases (e.g., MxaF1 and XoxF1-5) of known but also unusual genera (i.e., Methylomirabilis, Methylooceanibacter, Gemmatimonas, Verminephrobacter). 14C-methanol tracing of alive plant material revealed divergent potential methanol consumption rates in both plant species but similarly high rates in the rhizosphere and phyllosphere. CONCLUSIONS Our study revealed the rhizosphere as an overlooked hotspot for methanol consumption in temperate grasslands. We further identified unusual new but potentially relevant methanol utilizers besides well-known methylotrophs in the phyllosphere and rhizosphere. We did not observe a plant host-specific methanol utilizer community. Our results suggest that our approach using quantitative SIP and metagenomics may be useful in future field studies to link gross methanol consumption rates with the rhizosphere and phyllosphere microbiome.
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Affiliation(s)
- Saranya Kanukollu
- Microbial Biogeochemistry, RA1 Landscape Functioning, ZALF Leibniz Centre for Agricultural Landscape Research, Müncheberg, Germany
| | - Rainer Remus
- Isotope Biogeochemistry and Gas Fluxes, RA1 Landscape Functioning, ZALF Leibniz Centre for Agricultural Landscape Research, Müncheberg, Germany
| | | | - Caroline Buchen-Tschiskale
- Isotope Biogeochemistry and Gas Fluxes, RA1 Landscape Functioning, ZALF Leibniz Centre for Agricultural Landscape Research, Müncheberg, Germany
- Present Address: Johann Heinrich von Thünen-Institut, Institute of Climate-Smart Agriculture, Braunschweig, Germany
| | - Mathias Hoffmann
- Isotope Biogeochemistry and Gas Fluxes, RA1 Landscape Functioning, ZALF Leibniz Centre for Agricultural Landscape Research, Müncheberg, Germany
| | - Steffen Kolb
- Microbial Biogeochemistry, RA1 Landscape Functioning, ZALF Leibniz Centre for Agricultural Landscape Research, Müncheberg, Germany
- Thaer Institute, Faculty of Life Sciences, Humboldt University of Berlin, Berlin, Germany
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Tartaglia M, Zuzolo D, Postiglione A, Prigioniero A, Scarano P, Sciarrillo R, Guarino C. Biotechnological Combination for Co-contaminated Soil Remediation: Focus on Tripartite "Meta-Enzymatic" Activity. FRONTIERS IN PLANT SCIENCE 2022; 13:852513. [PMID: 35599908 PMCID: PMC9121008 DOI: 10.3389/fpls.2022.852513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 04/19/2022] [Indexed: 06/15/2023]
Abstract
Soil pollution is a pressing problem requiring solutions that can be applied without large-scale side effects directly in the field. Phytoremediation is an effective strategy combining plant and root-associated microbiome to immobilize, degrade, and adsorb pollutants from the soil. To improve phytoremediation, it is necessary to think of plants, fungi, and bacteria not as individual entities, but as a meta-organism that reacts organically, synergistically, and cooperatively to environmental stimuli. Analyzing the tripartite enzymatic activity in the rhizosphere is necessary to understand the mechanisms underlying plant-microorganism communication under abiotic stress (such as soil pollution). In this work, the potential of a microbial consortium along with a plant already known for its phytoremediation capabilities, Schedonorus arundinaceus (Scheb.) Dumort., was validated in a mesocosm experiment with pluricontaminated soil (heavy metals, PAHs, and PCBs). Chemical analyses of the soil at the beginning and end of the experiment confirmed the reduction of the main pollutants. The microscopic observation and chemical analyses confirmed the greater root colonization and pollutant removal following the microbial treatment. To obtain a taxonomic and functional picture, tripartite (plant, fungi, and bacteria) enzyme activity was assessed using a metatranscriptomic approach. Total RNA was extracted from a sample of rhizosphere sampled considering 2 centimeters of root and soil attached. From the total reads obtained, mRNAs were filtered, and analysis focused on reads identified as proteins with enzymatic activity. The differential analysis of transcripts identified as enzymes showed that a general increase in potential enzyme activity was observed in the rhizosphere after our biotechnological treatment. Also from a taxonomic perspective, an increase in the activity of some Phyla, such as Actinobacteria and Basidiomycota, was found in the treated sample compared to the control. An increased abundance of enzymes involved in rhizospheric activities and pollutant removal (such as dehydrogenase, urease, and laccase) was found in the treated sample compared to the control at the end of the experiment. Several enzymes expressed by the plant confirmed the increase in metabolic activity and architectural rearrangement of the root following the enhancement of the rhizospheric biome. The study provides new outcomes useful in rhizosphere engineering advancement.
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Soils and sediments host Thermoplasmata archaea encoding novel copper membrane monooxygenases (CuMMOs). THE ISME JOURNAL 2022; 16:1348-1362. [PMID: 34987183 PMCID: PMC9038741 DOI: 10.1038/s41396-021-01177-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 12/02/2021] [Accepted: 12/10/2021] [Indexed: 01/22/2023]
Abstract
Copper membrane monooxygenases (CuMMOs) play critical roles in the global carbon and nitrogen cycles. Organisms harboring these enzymes perform the first, and rate limiting, step in aerobic oxidation of ammonia, methane, or other simple hydrocarbons. Within archaea, only organisms in the order Nitrososphaerales (Thaumarchaeota) encode CuMMOs, which function exclusively as ammonia monooxygenases. From grassland and hillslope soils and aquifer sediments, we identified 20 genomes from distinct archaeal species encoding divergent CuMMO sequences. These archaea are phylogenetically clustered in a previously unnamed Thermoplasmatota order, herein named the Ca. Angelarchaeales. The CuMMO proteins in Ca. Angelarchaeales are more similar in structure to those in Nitrososphaerales than those of bacteria, and contain all functional residues required for general monooxygenase activity. Ca. Angelarchaeales genomes are significantly enriched in blue copper proteins (BCPs) relative to sibling lineages, including plastocyanin-like electron carriers and divergent nitrite reductase-like (nirK) 2-domain cupredoxin proteins co-located with electron transport machinery. Ca. Angelarchaeales also encode significant capacity for peptide/amino acid uptake and degradation and share numerous electron transport mechanisms with the Nitrososphaerales. Ca. Angelarchaeales are detected at high relative abundance in some of the environments where their genomes originated from. While the exact substrate specificities of the novel CuMMOs identified here have yet to be determined, activity on ammonia is possible given their metabolic and ecological context. The identification of an archaeal CuMMO outside of the Nitrososphaerales significantly expands the known diversity of CuMMO enzymes in archaea and suggests previously unaccounted organisms contribute to critical global nitrogen and/or carbon cycling functions.
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Metagenomic analysis of bacterial communities of Wadi Namar Lake, Riyadh, Saudi Arabia. Saudi J Biol Sci 2022; 29:3749-3758. [PMID: 35844383 PMCID: PMC9280250 DOI: 10.1016/j.sjbs.2022.03.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Revised: 02/08/2022] [Accepted: 03/02/2022] [Indexed: 11/23/2022] Open
Abstract
Wadi Namar lake is a new touristic attraction area in the south of Riyadh. Human activities around the lake may lead to changes in water quality with subsequent changes in microenvironment components including microbial diversity. The current study was designed to assess possible changes in bacterial communities of the water at Wadi Namar Lake. Therefore, water samples were collected from three different locations along the lake: L1 (no human activities, no plants), L2 (no human activity, some plants) and L3 (human activities, municipal wastes and some plants). The total DNA of the samples was extracted and subjected to 16S rDNA sequencing and metagenomic analysis; water pH, electrical conductivity (EC), total dissolved solids (TDS) as well as the concentration of Na+1, K+1, Cl−1 and total N were analysed. Metagenomic analysis showed variations in relative abundance of 17 phyla, 31 families, 43 genera and 19 species of bacteria between the locations. Proteobacteria was the most abundant phylum in all locations; however, its highest abundance was in L1. Planctomycete phylum was highly abundant in L1 and L3, while its abundance in L2 was low. The phyla Acidobacteria, Candidatus Saccharibacteria, Nitrospirae and Chloroflexi were associated with high TDS, EC, K+1 and Cl−1 concentrations in L3; various human activities around this location had possibly affected microbial diversity. Current study results help in recognising the structure of bacterial communities at Wadi Namar Lake in relation to their surroundings for planning to environment protection and future restoration of affected ecosystems.
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Ahrens CH, Wade JT, Champion MM, Langer JD. A Practical Guide to Small Protein Discovery and Characterization Using Mass Spectrometry. J Bacteriol 2022; 204:e0035321. [PMID: 34748388 PMCID: PMC8765459 DOI: 10.1128/jb.00353-21] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Small proteins of up to ∼50 amino acids are an abundant class of biomolecules across all domains of life. Yet due to the challenges inherent in their size, they are often missed in genome annotations, and are difficult to identify and characterize using standard experimental approaches. Consequently, we still know few small proteins even in well-studied prokaryotic model organisms. Mass spectrometry (MS) has great potential for the discovery, validation, and functional characterization of small proteins. However, standard MS approaches are poorly suited to the identification of both known and novel small proteins due to limitations at each step of a typical proteomics workflow, i.e., sample preparation, protease digestion, liquid chromatography, MS data acquisition, and data analysis. Here, we outline the major MS-based workflows and bioinformatic pipelines used for small protein discovery and validation. Special emphasis is placed on highlighting the adjustments required to improve detection and data quality for small proteins. We discuss both the unbiased detection of small proteins and the targeted analysis of small proteins of interest. Finally, we provide guidelines to prioritize novel small proteins, and an outlook on methods with particular potential to further improve comprehensive discovery and characterization of small proteins.
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Affiliation(s)
- Christian H. Ahrens
- Agroscope, Method Development and Analytics & SIB Swiss Institute of Bioinformatics, Wädenswil, Switzerland
| | - Joseph T. Wade
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
- Department of Biomedical Sciences, School of Public Health, University at Albany, Albany, New York, USA
| | - Matthew M. Champion
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA
| | - Julian D. Langer
- Mass Spectrometry and Proteomics, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
- Proteomics, Max Planck Institute for Brain Research, Frankfurt am Main, Germany
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Rokubacteria in Northern Peatlands: Habitat Preferences and Diversity Patterns. Microorganisms 2021; 10:microorganisms10010011. [PMID: 35056460 PMCID: PMC8780371 DOI: 10.3390/microorganisms10010011] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 12/16/2021] [Accepted: 12/20/2021] [Indexed: 01/04/2023] Open
Abstract
Rokubacteria is a phylogenetic clade of as-yet-uncultivated prokaryotes, which are detected in diverse terrestrial habitats and are commonly addressed as members of the rare biosphere. This clade was originally described as a candidate phylum; however, based on the results of comparative genome analysis, was later defined as the order-level lineage, Rokubacteriales, within the phylum Methylomirabilota. The physiology and lifestyles of these bacteria are poorly understood. A dataset of 16S rRNA gene reads retrieved from four boreal raised bogs and six eutrophic fens was examined for the presence of the Rokubacteriales; the latter were detected exclusively in fens. Their relative abundance varied between 0.2 and 4% of all bacteria and was positively correlated with pH, total nitrogen content, and availability of Ca and Mg. To test an earlier published hypothesis regarding the presence of methanotrophic capabilities in Rokubacteria, peat samples were incubated with 10% methane for four weeks. No response to methane availability was detected for the Rokubacteriales, while clear a increase in relative abundance was observed for the conventional Methylococcales methanotrophs. The search for methane monooxygenase encoding genes in 60 currently available Rokubacteriales metagenomes yielded negative results, although copper-containing monooxygenases were encoded by some members of this order. This study suggests that peat-inhabiting Rokubacteriales are neutrophilic non-methanotrophic bacteria that colonize nitrogen-rich wetlands.
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Stable-Isotope-Informed, Genome-Resolved Metagenomics Uncovers Potential Cross-Kingdom Interactions in Rhizosphere Soil. mSphere 2021; 6:e0008521. [PMID: 34468166 PMCID: PMC8550312 DOI: 10.1128/msphere.00085-21] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The functioning, health, and productivity of soil are intimately tied to a complex network of interactions, particularly in plant root-associated rhizosphere soil. We conducted a stable-isotope-informed, genome-resolved metagenomic study to trace carbon from Avena fatua grown in a 13CO2 atmosphere into soil. We collected paired rhizosphere and nonrhizosphere soil at 6 and 9 weeks of plant growth and extracted DNA that was then separated by density using ultracentrifugation. Thirty-two fractions from each of five samples were grouped by density, sequenced, assembled, and binned to generate 55 unique bacterial genomes that were ≥70% complete. We also identified complete 18S rRNA sequences of several 13C-enriched microeukaryotic bacterivores and fungi. We generated 10 circularized bacteriophage (phage) genomes, some of which were the most labeled entities in the rhizosphere, suggesting that phage may be important agents of turnover of plant-derived C in soil. CRISPR locus targeting connected one of these phage to a Burkholderiales host predicted to be a plant pathogen. Another highly labeled phage is predicted to replicate in a Catenulispora sp., a possible plant growth-promoting bacterium. We searched the genome bins for traits known to be used in interactions involving bacteria, microeukaryotes, and plant roots and found DNA from heavily 13C-labeled bacterial genes thought to be involved in modulating plant signaling hormones, plant pathogenicity, and defense against microeukaryote grazing. Stable-isotope-informed, genome-resolved metagenomics indicated that phage can be important agents of turnover of plant-derived carbon in soil. IMPORTANCE Plants grow in intimate association with soil microbial communities; these microbes can facilitate the availability of essential resources to plants. Thus, plant productivity commonly depends on interactions with rhizosphere bacteria, viruses, and eukaryotes. Our work is significant because we identified the organisms that took up plant-derived organic C in rhizosphere soil and determined that many of the active bacteria are plant pathogens or can impact plant growth via hormone modulation. Further, by showing that bacteriophage accumulate CO2-derived carbon, we demonstrated their vital roles in redistribution of plant-derived C into the soil environment through bacterial cell lysis. The use of stable-isotope probing (SIP) to identify consumption (or lack thereof) of root-derived C by key microbial community members within highly complex microbial communities opens the way for assessing manipulations of bacteria and phage with potentially beneficial and detrimental traits, ultimately providing a path to improved plant health and soil carbon storage.
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Yadav A, Borrelli JC, Elshahed MS, Youssef NH. Genomic Analysis of Family UBA6911 (Group 18 Acidobacteria) Expands the Metabolic Capacities of the Phylum and Highlights Adaptations to Terrestrial Habitats. Appl Environ Microbiol 2021; 87:e0094721. [PMID: 34160232 PMCID: PMC8357285 DOI: 10.1128/aem.00947-21] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 06/14/2021] [Indexed: 12/19/2022] Open
Abstract
Approaches for recovering and analyzing genomes belonging to novel, hitherto-unexplored bacterial lineages have provided invaluable insights into the metabolic capabilities and ecological roles of yet-uncultured taxa. The phylum Acidobacteria is one of the most prevalent and ecologically successful lineages on Earth, yet currently, multiple lineages within this phylum remain unexplored. Here, we utilize genomes recovered from Zodletone Spring, an anaerobic sulfide and sulfur-rich spring in southwestern Oklahoma, as well as from multiple disparate soil and nonsoil habitats, to examine the metabolic capabilities and ecological role of members of family UBA6911 (group 18) Acidobacteria. The analyzed genomes clustered into five distinct genera, with genera Gp18_AA60 and QHZH01 recovered from soils, genus Ga0209509 from anaerobic digestors, and genera Ga0212092 and UBA6911 from freshwater habitats. All genomes analyzed suggested that members of Acidobacteria group 18 are metabolically versatile heterotrophs capable of utilizing a wide range of proteins, amino acids, and sugars as carbon sources, possess respiratory and fermentative capacities, and display few auxotrophies. Soil-dwelling genera were characterized by larger genome sizes, higher numbers of CRISPR loci, an expanded carbohydrate active enzyme (CAZyme) machinery enabling debranching of specific sugars from polymers, possession of a C1 (methanol and methylamine) degradation machinery, and a sole dependence on aerobic respiration. In contrast, nonsoil genomes encoded a more versatile respiratory capacity for oxygen, nitrite, sulfate, and trimethylamine N-oxide (TMAO) respiration, as well as the potential for utilizing the Wood-Ljungdahl (WL) pathway as an electron sink during heterotrophic growth. Our results not only expand our knowledge of the metabolism of a yet-uncultured bacterial lineage but also provide interesting clues on how terrestrialization and niche adaptation drive metabolic specialization within the Acidobacteria. IMPORTANCE Members of the Acidobacteria are important players in global biogeochemical cycles, especially in soils. A wide range of acidobacterial lineages remain currently unexplored. We present a detailed genomic characterization of genomes belonging to family UBA6911 (also known as group 18) within the phylum Acidobacteria. The genomes belong to different genera and were obtained from soil (genera Gp18_AA60 and QHZH01), freshwater habitats (genera Ga0212092 and UBA6911), and an anaerobic digestor (genus Ga0209509). While all members of the family shared common metabolic features, e.g., heterotrophic respiratory abilities, broad substrate utilization capacities, and few auxotrophies, distinct differences between soil and nonsoil genera were observed. Soil genera were characterized by expanded genomes, higher numbers of CRISPR loci, a larger carbohydrate active enzyme (CAZyme) repertoire enabling monomer extractions from polymer side chains, and methylotrophic (methanol and methylamine) degradation capacities. In contrast, nonsoil genera encoded more versatile respiratory capacities for utilizing nitrite, sulfate, TMAO, and the WL pathway, in addition to oxygen as electron acceptors. Our results not only broaden our understanding of the metabolic capacities within the Acidobacteria but also provide interesting clues on how terrestrialization shaped Acidobacteria evolution and niche adaptation.
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Affiliation(s)
- Archana Yadav
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Jenna C. Borrelli
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, Oklahoma, 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
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Comparative Genomics Reveals Thermal Adaptation and a High Metabolic Diversity in " Candidatus Bathyarchaeia". mSystems 2021; 6:e0025221. [PMID: 34282939 PMCID: PMC8407382 DOI: 10.1128/msystems.00252-21] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
"Candidatus Bathyarchaeia" is a phylogenetically diverse and widely distributed lineage often in high abundance in anoxic submarine sediments; however, their evolution and ecological roles in terrestrial geothermal habitats are poorly understood. In the present study, 35 Ca. Bathyarchaeia metagenome-assembled genomes (MAGs) were recovered from hot spring sediments in Tibet and Yunnan, China. Phylogenetic analysis revealed all MAGs of Ca. Bathyarchaeia can be classified into 7 orders and 15 families. Among them, 4 families have been first discovered in the present study, significantly expanding the known diversity of Ca. Bathyarchaeia. Comparative genomics demonstrated Ca. Bathyarchaeia MAGs from thermal habitats to encode a large variety of genes related to carbohydrate degradation, which are likely a metabolic adaptation of these organisms to a lifestyle at high temperatures. At least two families are potential methanogens/alkanotrophs, indicating a potential for the catalysis of short-chain hydrocarbons. Three MAGs from Family-7.3 are identified as alkanotrophs due to the detection of an Mcr complex. Family-2 contains the largest number of genes relevant to alkyl-CoM transformation, indicating the potential for methylotrophic methanogenesis, although their evolutionary history suggests the ancestor of Ca. Bathyarchaeia was unable to metabolize alkanes. Subsequent lineages have acquired the ability via horizontal gene transfer. Overall, our study significantly expands our knowledge and understanding of the metabolic capabilities, habitat adaptations, and evolution of Ca. Bathyarchaeia in thermal environments. IMPORTANCE Ca. Bathyarchaeia MAGs from terrestrial hot spring habitats are poorly revealed, though they have been studied extensively in marine ecosystems. In this study, we uncovered the metabolic capabilities and ecological role of Ca. Bathyarchaeia in hot springs and give a comprehensive comparative analysis between thermal and nonthermal habitats to reveal the thermal adaptability of Ca. Bathyarchaeia. Also, we attempt to determine the evolutionary history of methane/alkane metabolism in Ca. Bathyarchaeia, since it appears to be the first archaea beyond Euryarchaeota which contains the mcrABG genes. The reclassification of Ca. Bathyarchaeia and significant genomic differences among different lineages largely expand our knowledge on these cosmopolitan archaea, which will be beneficial in guiding the future studies.
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Feng S, Sterzenbach R, Guo X. Deep learning for peptide identification from metaproteomics datasets. J Proteomics 2021; 247:104316. [PMID: 34246788 DOI: 10.1016/j.jprot.2021.104316] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Revised: 06/02/2021] [Accepted: 06/18/2021] [Indexed: 10/20/2022]
Abstract
Metaproteomics is becoming widely used in microbiome research for gaining insights into the functional state of the microbial community. Current metaproteomics studies are generally based on high-throughput tandem mass spectrometry (MS/MS) coupled with liquid chromatography. In this paper, we proposed a deep-learning-based algorithm, named DeepFilter, for improving peptide identifications from a collection of tandem mass spectra. The key advantage of the DeepFilter is that it does not need ad hoc training or fine-tuning as in existing filtering tools. DeepFilter is freely available under the GNU GPL license at https://github.com/Biocomputing-Research-Group/DeepFilter. SIGNIFICANCE: The identification of peptides and proteins from MS data involves the computational procedure of searching MS/MS spectra against a predefined protein sequence database and assigning top-scored peptides to spectra. Existing computational tools are still far from being able to extract all the information out of MS/MS data sets acquired from metaproteome samples. Systematical experiment results demonstrate that the DeepFilter identified up to 12% and 9% more peptide-spectrum-matches and proteins, respectively, compared with existing filtering algorithms, including Percolator, Q-ranker, PeptideProphet, and iProphet, on marine and soil microbial metaproteome samples with false discovery rate at 1%. The taxonomic analysis shows that DeepFilter found up to 7%, 10%, and 14% more species from marine, soil, and human gut samples compared with existing filtering algorithms. Therefore, DeepFilter was believed to generalize properly to new, previously unseen peptide-spectrum-matches and can be readily applied in peptide identification from metaproteomics data.
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Affiliation(s)
- Shichao Feng
- Department of Computer Science and Engineering, University of North Texas, TX, USA
| | - Ryan Sterzenbach
- Department of Biomedical Engineering, University of North Texas, TX, USA
| | - Xuan Guo
- Department of Computer Science and Engineering, University of North Texas, TX, USA.
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Extracellular and Intracellular Lanthanide Accumulation in the Methylotrophic Beijerinckiaceae Bacterium RH AL1. Appl Environ Microbiol 2021; 87:e0314420. [PMID: 33893117 PMCID: PMC8316094 DOI: 10.1128/aem.03144-20] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Recent work with Methylorubrum extorquens AM1 identified intracellular, cytoplasmic lanthanide storage in an organism that harnesses these metals for its metabolism. Here, we describe the extracellular and intracellular accumulation of lanthanides in the Beijerinckiaceae bacterium RH AL1, a newly isolated and recently characterized methylotroph. Using ultrathin-section transmission electron microscopy (TEM), freeze fracture TEM (FFTEM), and energy-dispersive X-ray spectroscopy, we demonstrated that strain RH AL1 accumulates lanthanides extracellularly at outer membrane vesicles (OMVs) and stores them in the periplasm. High-resolution elemental analyses of biomass samples revealed that strain RH AL1 can accumulate ions of different lanthanide species, with a preference for heavier lanthanides. Its methanol oxidation machinery is supposedly adapted to light lanthanides, and their selective uptake is mediated by dedicated uptake mechanisms. Based on transcriptome sequencing (RNA-seq) analysis, these presumably include the previously characterized TonB-ABC transport system encoded by the lut cluster but potentially also a type VI secretion system. A high level of constitutive expression of genes coding for lanthanide-dependent enzymes suggested that strain RH AL1 maintains a stable transcript pool to flexibly respond to changing lanthanide availability. Genes coding for lanthanide-dependent enzymes are broadly distributed taxonomically. Our results support the hypothesis that central aspects of lanthanide-dependent metabolism partially differ between the various taxa. IMPORTANCE Although multiple pieces of evidence have been added to the puzzle of lanthanide-dependent metabolism, we are still far from understanding the physiological role of lanthanides. Given how widespread lanthanide-dependent enzymes are, only limited information is available with respect to how lanthanides are taken up and stored in an organism. Our research complements work with commonly studied model organisms and showed the localized storage of lanthanides in the periplasm. This storage occurred at comparably low concentrations. Strain RH AL1 is able to accumulate lanthanide ions extracellularly and to selectively utilize lighter lanthanides. The Beijerinckiaceae bacterium RH AL1 might be an attractive target for developing biorecovery strategies to obtain these economically highly demanded metals in environmentally friendly ways.
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20
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Murphy CL, Sheremet A, Dunfield PF, Spear JR, Stepanauskas R, Woyke T, Elshahed MS, Youssef NH. Genomic Analysis of the Yet-Uncultured Binatota Reveals Broad Methylotrophic, Alkane-Degradation, and Pigment Production Capacities. mBio 2021; 12:e00985-21. [PMID: 34006650 PMCID: PMC8262859 DOI: 10.1128/mbio.00985-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Accepted: 04/07/2021] [Indexed: 01/18/2023] Open
Abstract
The recent leveraging of genome-resolved metagenomics has generated an enormous number of genomes from novel uncultured microbial lineages yet left many clades undescribed. Here, we present a global analysis of genomes belonging to Binatota (UBP10), a globally distributed, yet-uncharacterized bacterial phylum. All orders in Binatota encoded the capacity for aerobic methylotrophy using methanol, methylamine, sulfomethanes, and chloromethanes as the substrates. Methylotrophy in Binatota was characterized by order-specific substrate degradation preferences, as well as extensive metabolic versatility, i.e., the utilization of diverse sets of genes, pathways, and combinations to achieve a specific metabolic goal. The genomes also encoded multiple alkane hydroxylases and monooxygenases, potentially enabling growth on a wide range of alkanes and fatty acids. Pigmentation is inferred from a complete pathway for carotenoids (lycopene, β- and γ-carotenes, xanthins, chlorobactenes, and spheroidenes) production. Further, the majority of genes involved in bacteriochlorophyll a, c, and d biosynthesis were identified, although absence of key genes and failure to identify a photosynthetic reaction center preclude proposing phototrophic capacities. Analysis of 16S rRNA databases showed the preferences of Binatota to terrestrial and freshwater ecosystems, hydrocarbon-rich habitats, and sponges, supporting their potential role in mitigating methanol and methane emissions, breakdown of alkanes, and their association with sponges. Our results expand the lists of methylotrophic, aerobic alkane-degrading, and pigment-producing lineages. We also highlight the consistent encountering of incomplete biosynthetic pathways in microbial genomes, a phenomenon necessitating careful assessment when assigning putative functions based on a set-threshold of pathway completion.IMPORTANCE A wide range of microbial lineages remain uncultured, yet little is known regarding their metabolic capacities, physiological preferences, and ecological roles in various ecosystems. We conducted a thorough comparative genomic analysis of 108 genomes belonging to the Binatota (UBP10), a globally distributed, yet-uncharacterized bacterial phylum. We present evidence that members of the order Binatota specialize in methylotrophy and identify an extensive repertoire of genes and pathways mediating the oxidation of multiple one-carbon (C1) compounds in Binatota genomes. The occurrence of multiple alkane hydroxylases and monooxygenases in these genomes was also identified, potentially enabling growth on a wide range of alkanes and fatty acids. Pigmentation is inferred from a complete pathway for carotenoids production. We also report on the presence of incomplete chlorophyll biosynthetic pathways in all genomes and propose several evolutionary-grounded scenarios that could explain such a pattern. Assessment of the ecological distribution patterns of the Binatota indicates preference of its members to terrestrial and freshwater ecosystems characterized by high methane and methanol emissions, as well as multiple hydrocarbon-rich habitats and marine sponges.
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Affiliation(s)
- Chelsea L Murphy
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Andriy Sheremet
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada
| | - Peter F Dunfield
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada
| | - John R Spear
- Civil and Environmental Engineering, Colorado School of Mines, Golden, Colorado, USA
| | | | - Tanja Woyke
- Department of Energy Joint Genome Institute, Berkley, California, 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
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Viljakainen VR, Hug LA. The phylogenetic and global distribution of bacterial polyhydroxyalkanoate bioplastic-degrading genes. Environ Microbiol 2021; 23:1717-1731. [PMID: 33496062 DOI: 10.1111/1462-2920.15409] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 01/04/2021] [Accepted: 01/18/2021] [Indexed: 11/30/2022]
Abstract
Polyhydroxyalkanoates (PHAs) are a family of microbially made polyesters commercialized as biodegradable plastics. PHA production rates are predicted to increase as concerns around environmental plastic contamination and limited fossil fuel resources have increased the importance of biodegradable and bio-based plastic alternatives. Microbially produced PHA depolymerases are the key enzymes mediating PHA biodegradation, but only a few PHA depolymerases have been well-characterized and screens employing metagenomic sequence data are lacking. Here, we used 3078 metagenomes to analyse the distribution of PHA depolymerases in microbial communities from diverse aquatic, terrestrial and waste management systems. We significantly expand the recognized diversity of this protein family by screening 1914 Gb of sequence data and identifying 13 869 putative PHA depolymerases in 1295 metagenomes. Our results indicate that PHA depolymerases are unevenly distributed across environments. We predicted the highest frequency of PHA depolymerases in wastewater systems and the lowest in marine and thermal springs. In tandem, we screened 5290 metagenome-assembled genomes to describe the phylogenetic distribution of PHA depolymerases, which is substantially broader compared with current cultured representatives. The Proteobacteria and Bacteroidota are key lineages encoding PHA depolymerases, but PHA depolymerases were predicted from members of the Bdellovibrionota, Methylomirabilota, Actinobacteriota, Firmicutes, Spirochaetota, Desulfobacterota, Myxococcota and Planctomycetota.
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Affiliation(s)
- V R Viljakainen
- University of Waterloo, 200 University Ave. West, Waterloo, ON, N2L 3G1, Canada
| | - L A Hug
- University of Waterloo, 200 University Ave. West, Waterloo, ON, N2L 3G1, Canada
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Chiba A, Uchida Y, Kublik S, Vestergaard G, Buegger F, Schloter M, Schulz S. Soil Bacterial Diversity Is Positively Correlated with Decomposition Rates during Early Phases of Maize Litter Decomposition. Microorganisms 2021; 9:microorganisms9020357. [PMID: 33670245 PMCID: PMC7916959 DOI: 10.3390/microorganisms9020357] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 02/07/2021] [Accepted: 02/09/2021] [Indexed: 12/16/2022] Open
Abstract
This study aimed to investigate the effects of different levels of soil- and plant-associated bacterial diversity on the rates of litter decomposition, and bacterial community dynamics during its early phases. We performed an incubation experiment where soil bacterial diversity (but not abundance) was manipulated by autoclaving and reinoculation. Natural or autoclaved maize leaves were applied to the soils and incubated for 6 weeks. Bacterial diversity was assessed before and during litter decomposition using 16S rRNA gene metabarcoding. We found a positive correlation between litter decomposition rates and soil bacterial diversity. The soil with the highest bacterial diversity was dominated by oligotrophic bacteria including Acidobacteria, Nitrospiraceae, and Gaiellaceae, and its community composition did not change during the incubation. In the less diverse soils, those taxa were absent but were replaced by copiotrophic bacteria, such as Caulobacteraceae and Beijerinckiaceae, until the end of the incubation period. SourceTracker analysis revealed that litter-associated bacteria, such as Beijerinckiaceae, only became part of the bacterial communities in the less diverse soils. This suggests a pivotal role of oligotrophic bacteria during the early phases of litter decomposition and the predominance of copiotrophic bacteria at low diversity.
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Affiliation(s)
- Akane Chiba
- Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan; (A.C.); (Y.U.)
- Research Unit Comparative Microbiome Analysis, Helmholtz Zentrum München, German Research Centre for Environmental Health, 85764 Neuherberg, Germany; (S.K.); (G.V.); (M.S.)
- Crop Physiology, TUM School of Life Science, Technical University of Munich, 85354 Freising, Germany
| | - Yoshitaka Uchida
- Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan; (A.C.); (Y.U.)
| | - Susanne Kublik
- Research Unit Comparative Microbiome Analysis, Helmholtz Zentrum München, German Research Centre for Environmental Health, 85764 Neuherberg, Germany; (S.K.); (G.V.); (M.S.)
| | - Gisle Vestergaard
- Research Unit Comparative Microbiome Analysis, Helmholtz Zentrum München, German Research Centre for Environmental Health, 85764 Neuherberg, Germany; (S.K.); (G.V.); (M.S.)
- Section of Bioinformatics, Department of Health Technology, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - Franz Buegger
- Institute of Biochemical Plant Pathology, Helmholtz Zentrum München, German Research Centre for Environmental Health, 85764 Neuherberg, Germany;
| | - Michael Schloter
- Research Unit Comparative Microbiome Analysis, Helmholtz Zentrum München, German Research Centre for Environmental Health, 85764 Neuherberg, Germany; (S.K.); (G.V.); (M.S.)
- TUM School of Life Science, Technical University of Munich, 85354 Freising, Germany
| | - Stefanie Schulz
- Research Unit Comparative Microbiome Analysis, Helmholtz Zentrum München, German Research Centre for Environmental Health, 85764 Neuherberg, Germany; (S.K.); (G.V.); (M.S.)
- Correspondence: ; Tel.: +49-(0)89-3187-3054
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Tartaglia M, Bastida F, Sciarrillo R, Guarino C. Soil Metaproteomics for the Study of the Relationships Between Microorganisms and Plants: A Review of Extraction Protocols and Ecological Insights. Int J Mol Sci 2020; 21:ijms21228455. [PMID: 33187080 PMCID: PMC7697097 DOI: 10.3390/ijms21228455] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 11/02/2020] [Accepted: 11/09/2020] [Indexed: 12/19/2022] Open
Abstract
Soil is a complex matrix where biotic and abiotic components establish a still unclear network involving bacteria, fungi, archaea, protists, protozoa, and roots that are in constant communication with each other. Understanding these interactions has recently focused on metagenomics, metatranscriptomics and less on metaproteomics studies. Metaproteomic allows total extraction of intracellular and extracellular proteins from soil samples, providing a complete picture of the physiological and functional state of the “soil community”. The advancement of high-performance mass spectrometry technologies was more rapid than the development of ad hoc extraction techniques for soil proteins. The protein extraction from environmental samples is biased due to interfering substances and the lower amount of proteins in comparison to cell cultures. Soil sample preparation and extraction methodology are crucial steps to obtain high-quality resolution and yields of proteins. This review focuses on the several soil protein extraction protocols to date to highlight the methodological challenges and critical issues for the application of proteomics to soil samples. This review concludes that improvements in soil protein extraction, together with the employment of ad hoc metagenome database, may enhance the identification of proteins with low abundance or from non-dominant populations and increase our capacity to predict functional changes in soil.
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Affiliation(s)
- Maria Tartaglia
- Department of Science and Technology, University of Sannio, via de Sanctis snc, 82100 Benevento, Italy; (M.T.); (R.S.)
| | - Felipe Bastida
- CEBAS-CSIC, Department of Soil and Water Conservation, Campus Universitario de Espinardo, 30100 Murcia, Spain;
| | - Rosaria Sciarrillo
- Department of Science and Technology, University of Sannio, via de Sanctis snc, 82100 Benevento, Italy; (M.T.); (R.S.)
| | - Carmine Guarino
- Department of Science and Technology, University of Sannio, via de Sanctis snc, 82100 Benevento, Italy; (M.T.); (R.S.)
- Correspondence: ; Tel.: +39-824-305145
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Qu B, Ma Z, Yao L, Gao Z, Zhang S. Preserved antibacterial activity of ribosomal protein S15 during evolution. Mol Immunol 2020; 127:57-66. [PMID: 32927165 DOI: 10.1016/j.molimm.2020.08.024] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 08/29/2020] [Accepted: 08/31/2020] [Indexed: 01/02/2023]
Abstract
Conventional role of ribosomal proteins is ribosome assembly and protein translation, but some ribosomal proteins also show antimicrobial peptide (AMP) activity, though their mode of action remains ill-defined. Here we demonstrated for the first time that amphioxus RPS15, BjRPS15, was a previously uncharacterized AMP, which was not only capable of identifying Gram-negative and -positive bacteria via interaction with LPS and LTA but also capable of killing the bacteria. We also showed that both the sequence and 3D structure of RPS15 and its prokaryotic homologs were highly conserved, suggesting its antibacterial activity is universal across widely separated taxa. Actually this was supported by the facts that the residues positioned at 45-67 formed the core region for the antimicrobial activity of BjRPS15, and its prokaryotic counterparts, including Nitrospirae RPS1933-55, Aquificae RPS1933-55 and P. syringae RPS1950-72, similarly displayed antibacterial activities. BjRPS15 functioned by both interaction with bacterial surface via LPS and LTA and membrane depolarization as well as induction of intracellular ROS. Moreover, we showed that RPS15 existed extracellularly in amphioxus, shrimp, zebrafish and mice, hinting it may play a critical role in systematic immunity in different animals. In addition, we found that neither BjRPS15 nor its truncated form BjRPS1545-67 were toxic to mammalian cells, making them promising lead molecules for the design of novel AMPs against bacteria. Collectively, these indicate that RPS15 is a new member of AMP with ancient origin and high conservation throughout evolution.
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Affiliation(s)
- Baozhen Qu
- Laboratory for Evolution & Development, Institute of Evolution & Marine Biodiversity and Department of Marine Biology, Ocean University of China, Qingdao, 266003, China
| | - Zengyu Ma
- Laboratory for Evolution & Development, Institute of Evolution & Marine Biodiversity and Department of Marine Biology, Ocean University of China, Qingdao, 266003, China
| | - Lan Yao
- Laboratory for Evolution & Development, Institute of Evolution & Marine Biodiversity and Department of Marine Biology, Ocean University of China, Qingdao, 266003, China
| | - Zhan Gao
- Laboratory for Evolution & Development, Institute of Evolution & Marine Biodiversity and Department of Marine Biology, Ocean University of China, Qingdao, 266003, China
| | - Shicui Zhang
- Laboratory for Evolution & Development, Institute of Evolution & Marine Biodiversity and Department of Marine Biology, Ocean University of China, Qingdao, 266003, China; Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, 266003, China.
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25
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Suleiman M, Krüger A, Antranikian G. Biomass-degrading glycoside hydrolases of archaeal origin. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:153. [PMID: 32905355 PMCID: PMC7469102 DOI: 10.1186/s13068-020-01792-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 08/22/2020] [Indexed: 06/11/2023]
Abstract
During the last decades, the impact of hyperthermophiles and their enzymes has been intensively investigated for implementation in various high-temperature biotechnological processes. Biocatalysts of hyperthermophiles have proven to show extremely high thermo-activities and thermo-stabilities and are identified as suitable candidates for numerous industrial processes with harsh conditions, including the process of an efficient plant biomass pretreatment and conversion. Already-characterized archaea-originated glycoside hydrolases (GHs) have shown highly impressive features and numerous enzyme characterizations indicated that these biocatalysts show maximum activities at a higher temperature range compared to bacterial ones. However, compared to bacterial biomass-degrading enzymes, the number of characterized archaeal ones remains low. To discover new promising archaeal GH candidates, it is necessary to study in detail the microbiology and enzymology of extremely high-temperature habitats, ranging from terrestrial to marine hydrothermal systems. State-of-the art technologies such as sequencing of genomes and metagenomes and automated binning of genomes out of metagenomes, combined with classical microbiological culture-dependent approaches, have been successfully performed to detect novel promising biomass-degrading hyperthermozymes. In this review, we will focus on the detection, characterization and similarities of archaeal GHs and their unique characteristics. The potential of hyperthermozymes and their impact on high-temperature industrial applications have not yet been exhausted.
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Affiliation(s)
- Marcel Suleiman
- Institute of Technical Microbiology, University of Technology Hamburg, Hamburg, Germany
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
| | - Anna Krüger
- Institute of Technical Microbiology, University of Technology Hamburg, Hamburg, Germany
| | - Garabed Antranikian
- Institute of Technical Microbiology, University of Technology Hamburg, Hamburg, Germany
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26
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Crits-Christoph A, Olm MR, Diamond S, Bouma-Gregson K, Banfield JF. Soil bacterial populations are shaped by recombination and gene-specific selection across a grassland meadow. THE ISME JOURNAL 2020; 14:1834-1846. [PMID: 32327732 PMCID: PMC7305173 DOI: 10.1038/s41396-020-0655-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 03/22/2020] [Accepted: 04/02/2020] [Indexed: 01/25/2023]
Abstract
Soil microbial diversity is often studied from the perspective of community composition, but less is known about genetic heterogeneity within species. The relative impacts of clonal interference, gene-specific selection, and recombination in many abundant but rarely cultivated soil microbes remain unknown. Here we track genome-wide population genetic variation for 19 highly abundant bacterial species sampled from across a grassland meadow. Genomic inferences about population structure are made using the millions of sequencing reads that are assembled de novo into consensus genomes from metagenomes, as each read pair describes a short genomic sequence from a cell in each population. Genomic nucleotide identity of assembled genomes was significantly associated with local geography for over half of the populations studied, and for a majority of populations within-sample nucleotide diversity could often be as high as meadow-wide nucleotide diversity. Genes involved in metabolite biosynthesis and extracellular transport were characterized by elevated nucleotide diversity in multiple species. Microbial populations displayed varying degrees of homologous recombination and recombinant variants were often detected at 7-36% of loci genome-wide. Within multiple populations we identified genes with unusually high spatial differentiation of alleles, fewer recombinant events, elevated ratios of nonsynonymous to synonymous variants, and lower nucleotide diversity, suggesting recent selective sweeps for gene variants. Taken together, these results indicate that recombination and gene-specific selection commonly shape genetic variation in several understudied soil bacterial lineages.
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Affiliation(s)
| | - Matthew R Olm
- Department of Earth and Planetary Science, University of California, Berkeley, CA, USA
| | - Spencer Diamond
- Department of Earth and Planetary Science, University of California, Berkeley, CA, USA
| | - Keith Bouma-Gregson
- Department of Earth and Planetary Science, University of California, Berkeley, CA, USA
| | - Jillian F Banfield
- Department of Earth and Planetary Science, University of California, Berkeley, CA, USA.
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA, USA.
- Earth Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
- Chan Zuckerberg Biohub, San Francisco, CA, USA.
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27
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Sharrar AM, Crits-Christoph A, Méheust R, Diamond S, Starr EP, Banfield JF. Bacterial Secondary Metabolite Biosynthetic Potential in Soil Varies with Phylum, Depth, and Vegetation Type. mBio 2020; 11:e00416-20. [PMID: 32546614 PMCID: PMC7298704 DOI: 10.1128/mbio.00416-20] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 05/08/2020] [Indexed: 01/12/2023] Open
Abstract
Bacteria isolated from soils are major sources of specialized metabolites, including antibiotics and other compounds with clinical value that likely shape interactions among microbial community members and impact biogeochemical cycles. Yet, isolated lineages represent a small fraction of all soil bacterial diversity. It remains unclear how the production of specialized metabolites varies across the phylogenetic diversity of bacterial species in soils and whether the genetic potential for production of these metabolites differs with soil depth and vegetation type within a geographic region. We sampled soils and saprolite from three sites in a northern California Critical Zone Observatory with various vegetation and bedrock characteristics and reconstructed 1,334 metagenome-assembled genomes containing diverse biosynthetic gene clusters (BGCs) for secondary metabolite production. We obtained genomes for prolific producers of secondary metabolites, including novel groups within the Actinobacteria, Chloroflexi, and candidate phylum "Candidatus Dormibacteraeota." Surprisingly, one genome of a candidate phyla radiation (CPR) bacterium coded for a ribosomally synthesized linear azole/azoline-containing peptide, a capacity we found in other publicly available CPR bacterial genomes. Overall, bacteria with higher biosynthetic potential were enriched in shallow soils and grassland soils, with patterns of abundance of BGC type varying by taxonomy.IMPORTANCE Microbes produce specialized compounds to compete or communicate with one another and their environment. Some of these compounds, such as antibiotics, are also useful in medicine and biotechnology. Historically, most antibiotics have come from soil bacteria which can be isolated and grown in the lab. Though the vast majority of soil bacteria cannot be isolated, we can extract their genetic information and search it for genes which produce these specialized compounds. These understudied soil bacteria offer a wealth of potential for the discovery of new and important microbial products. Here, we identified the ability to produce these specialized compounds in diverse and novel bacteria in a range of soil environments. This information will be useful to other researchers who wish to isolate certain products. Beyond their use to humans, understanding the distribution and function of microbial products is key to understanding microbial communities and their effects on biogeochemical cycles.
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Affiliation(s)
- Allison M Sharrar
- Department of Earth and Planetary Science, University of California, Berkeley, Berkeley, California, USA
| | - Alexander Crits-Christoph
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, California, USA
| | - Raphaël Méheust
- Department of Earth and Planetary Science, University of California, Berkeley, Berkeley, California, USA
- Innovative Genomics Institute, Berkeley, California, USA
| | - Spencer Diamond
- Department of Earth and Planetary Science, University of California, Berkeley, Berkeley, California, USA
| | - Evan P Starr
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, California, USA
| | - Jillian F Banfield
- Department of Earth and Planetary Science, University of California, Berkeley, Berkeley, California, USA
- Innovative Genomics Institute, Berkeley, California, USA
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Yan C, Zhang J, Wu P, Gan Y, Zhang G. An EDTA-resistant pyrazinamidase from non-pathogen Pseudonocardia carboxydivorans. Biotechnol Lett 2020; 42:1707-1718. [PMID: 32323078 DOI: 10.1007/s10529-020-02890-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 04/14/2020] [Indexed: 11/28/2022]
Abstract
OBJECTIVES To characterize a pyrazinamidase from non-pathogen Pseudonocardia carboxydivorans. RESULTS A pyrazinamidase gene pncA encoding a 23-kDa protein PncA-Pse from P. carboxydivorans was over-expressed in Escherichia coli and characterized. This PncA-Pse can convert both pyrazinamide and nicotinamide efficiently with the optimal pH and temperature of pH 8.5 and 45 °C, respectively. Although ferrous iron and manganese were detected in PncA-Pse, the enzymatic activity is not affected by EDTA with the final concentration of 10 mM. Moreover, the enzymatic activity was not significantly affected with the addition of several metal ions, respectively. Based on the structure modeling, the 61st histidine which is associated with the metal binding, was mutated into alanine to get mutant H61A. No activity, iron and manganese were detected for H61A, which implies that PncA-Pse is a metal enzyme with resistance of the metal ion chelator EDTA, which is different from the previous reports. CONCLUSION This is the first characterized pyrazinamidase from the genus Pseudonocardia, a non-pathogen.
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Affiliation(s)
- Chuang Yan
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan, 430062, Hubei, China
| | - Jingxuan Zhang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan, 430062, Hubei, China
| | - Pan Wu
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan, 430062, Hubei, China
| | - Yong Gan
- Zhejiang Anglikang Pharmaceutical Co., Ltd. Shengzhou, Shaoxing, 312400, Zhejiang, China
| | - Guimin Zhang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan, 430062, Hubei, China.
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Macey MC, Pratscher J, Crombie AT, Murrell JC. Impact of plants on the diversity and activity of methylotrophs in soil. MICROBIOME 2020; 8:31. [PMID: 32156318 PMCID: PMC7065363 DOI: 10.1186/s40168-020-00801-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 02/10/2020] [Indexed: 05/16/2023]
Abstract
BACKGROUND Methanol is the second most abundant volatile organic compound in the atmosphere, with the majority produced as a metabolic by-product during plant growth. There is a large disparity between the estimated amount of methanol produced by plants and the amount which escapes to the atmosphere. This may be due to utilisation of methanol by plant-associated methanol-consuming bacteria (methylotrophs). The use of molecular probes has previously been effective in characterising the diversity of methylotrophs within the environment. Here, we developed and applied molecular probes in combination with stable isotope probing to identify the diversity, abundance and activity of methylotrophs in bulk and in plant-associated soils. RESULTS Application of probes for methanol dehydrogenase genes (mxaF, xoxF, mdh2) in bulk and plant-associated soils revealed high levels of diversity of methylotrophic bacteria within the bulk soil, including Hyphomicrobium, Methylobacterium and members of the Comamonadaceae. The community of methylotrophic bacteria captured by this sequencing approach changed following plant growth. This shift in methylotrophic diversity was corroborated by identification of the active methylotrophs present in the soils by DNA stable isotope probing using 13C-labelled methanol. Sequencing of the 16S rRNA genes and construction of metagenomes from the 13C-labelled DNA revealed members of the Methylophilaceae as highly abundant and active in all soils examined. There was greater diversity of active members of the Methylophilaceae and Comamonadaceae and of the genus Methylobacterium in plant-associated soils compared to the bulk soil. Incubating growing pea plants in a 13CO2 atmosphere revealed that several genera of methylotrophs, as well as heterotrophic genera within the Actinomycetales, assimilated plant exudates in the pea rhizosphere. CONCLUSION In this study, we show that plant growth has a major impact on both the diversity and the activity of methanol-utilising methylotrophs in the soil environment, and thus, the study contributes significantly to efforts to balance the terrestrial methanol and carbon cycle. Video abstract.
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Affiliation(s)
- Michael C. Macey
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ UK
- AstrobiologyOU, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes, Buckinghamshire MK7 6AA UK
| | - Jennifer Pratscher
- The Lyell Centre, School of Energy, Geoscience, Infrastructure and Society, Heriot-Watt University, Research Avenue South, Edinburgh, EH14 4AP UK
| | - Andrew T. Crombie
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ UK
| | - J. Colin Murrell
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ UK
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30
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Starr EP, Nuccio EE, Pett-Ridge J, Banfield JF, Firestone MK. Metatranscriptomic reconstruction reveals RNA viruses with the potential to shape carbon cycling in soil. Proc Natl Acad Sci U S A 2019; 116:25900-25908. [PMID: 31772013 PMCID: PMC6926006 DOI: 10.1073/pnas.1908291116] [Citation(s) in RCA: 105] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Viruses impact nearly all organisms on Earth, with ripples of influence in agriculture, health, and biogeochemical processes. However, very little is known about RNA viruses in an environmental context, and even less is known about their diversity and ecology in soil, 1 of the most complex microbial systems. Here, we assembled 48 individual metatranscriptomes from 4 habitats within a planted soil sampled over a 22-d time series: Rhizosphere alone, detritosphere alone, rhizosphere with added root detritus, and unamended soil (4 time points and 3 biological replicates). We resolved the RNA viral community, uncovering a high diversity of viral sequences. We also investigated possible host organisms by analyzing metatranscriptome marker genes. Based on viral phylogeny, much of the diversity was Narnaviridae that may parasitize fungi or Leviviridae, which may infect Proteobacteria. Both host and viral communities appear to be highly dynamic, and rapidly diverged depending on experimental conditions. The viral and host communities were structured based on the presence of root litter. Clear temporal dynamics by Leviviridae and their hosts indicated that viruses were replicating. With this time-resolved analysis, we show that RNA viruses are diverse, abundant, and active in soil. When viral infection causes host cell death, it may mobilize cell carbon in a process that may represent an overlooked component of soil carbon cycling.
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Affiliation(s)
- Evan P Starr
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720
| | - Erin E Nuccio
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550
| | - Jennifer Pett-Ridge
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550
| | - Jillian F Banfield
- Department of Earth and Planetary Science, University of California, Berkeley, CA 94720;
- Earth Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA 94720
- Chan Zuckerberg Biohub, San Francisco, CA 94158
- Innovative Genomics Institute, Berkeley, CA 94720
| | - Mary K Firestone
- Earth Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720;
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA 94720
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31
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Lanthanide-Dependent Methylotrophs of the Family Beijerinckiaceae: Physiological and Genomic Insights. Appl Environ Microbiol 2019; 86:AEM.01830-19. [PMID: 31604774 DOI: 10.1128/aem.01830-19] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 10/07/2019] [Indexed: 01/07/2023] Open
Abstract
Methylotrophic bacteria use methanol and related C1 compounds as carbon and energy sources. Methanol dehydrogenases are essential for methanol oxidation, while lanthanides are important cofactors of many pyrroloquinoline quinone-dependent methanol dehydrogenases and related alcohol dehydrogenases. We describe here the physiological and genomic characterization of newly isolated Beijerinckiaceae bacteria that rely on lanthanides for methanol oxidation. A broad physiological diversity was indicated by the ability to metabolize a wide range of multicarbon substrates, including various sugars, and organic acids, as well as diverse C1 substrates such as methylated amines and methylated sulfur compounds. Methanol oxidation was possible only in the presence of low-mass lanthanides (La, Ce, and Nd) at submicromolar concentrations (>100 nM). In a comparison with other Beijerinckiaceae, genomic and transcriptomic analyses revealed the usage of a glutathione- and tetrahydrofolate-dependent pathway for formaldehyde oxidation and channeling methyl groups into the serine cycle for carbon assimilation. Besides a single xoxF gene, we identified two additional genes for lanthanide-dependent alcohol dehydrogenases, including one coding for an ExaF-type alcohol dehydrogenase, which was so far not known in Beijerinckiaceae Homologs for most of the gene products of the recently postulated gene cluster linked to lanthanide utilization and transport could be detected, but for now it remains unanswered how lanthanides are sensed and taken up by our strains. Studying physiological responses to lanthanides under nonmethylotrophic conditions in these isolates as well as other organisms is necessary to gain a more complete understanding of lanthanide-dependent metabolism as a whole.IMPORTANCE We supplemented knowledge of the broad metabolic diversity of the Beijerinckiaceae by characterizing new members of this family that rely on lanthanides for methanol oxidation and that possess additional lanthanide-dependent enzymes. Considering that lanthanides are critical resources for many modern applications and that recovering them is expensive and puts a heavy burden on the environment, lanthanide-dependent metabolism in microorganisms is an exploding field of research. Further research into how isolated Beijerinckiaceae and other microbes utilize lanthanides is needed to increase our understanding of lanthanide-dependent metabolism. The diversity and widespread occurrence of lanthanide-dependent enzymes make it likely that lanthanide utilization varies in different taxonomic groups and is dependent on the habitat of the microbes.
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32
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Li Z, Yao Q, Guo X, Crits-Christoph A, Mayes MA, Hervey WJ, Lebeis SL, Banfield JF, Hurst GB, Hettich RL, Pan C. Genome-Resolved Proteomic Stable Isotope Probing of Soil Microbial Communities Using 13CO 2 and 13C-Methanol. Front Microbiol 2019; 10:2706. [PMID: 31866955 PMCID: PMC6908837 DOI: 10.3389/fmicb.2019.02706] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Accepted: 11/08/2019] [Indexed: 11/15/2022] Open
Abstract
Stable isotope probing (SIP) enables tracking the nutrient flows from isotopically labeled substrates to specific microorganisms in microbial communities. In proteomic SIP, labeled proteins synthesized by the microbial consumers of labeled substrates are identified with a shotgun proteomics approach. Here, proteomic SIP was combined with targeted metagenomic binning to reconstruct metagenome-assembled genomes (MAGs) of the microorganisms producing labeled proteins. This approach was used to track carbon flows from 13CO2 to the rhizosphere communities of Zea mays, Triticum aestivum, and Arabidopsis thaliana. Rhizosphere microorganisms that assimilated plant-derived 13C were capable of metabolic and signaling interactions with their plant hosts, as shown by their MAGs containing genes for phytohormone modulation, quorum sensing, and transport and metabolism of nutrients typical of those found in root exudates. XoxF-type methanol dehydrogenases were among the most abundant proteins identified in the rhizosphere metaproteomes. 13C-methanol proteomic SIP was used to test the hypothesis that XoxF was used to metabolize and assimilate methanol in the rhizosphere. We detected 7 13C-labeled XoxF proteins and identified methylotrophic pathways in the MAGs of 8 13C-labeled microorganisms, which supported the hypothesis. These two studies demonstrated the capability of proteomic SIP for functional characterization of active microorganisms in complex microbial communities.
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Affiliation(s)
- Zhou Li
- Computer Science and Mathematics Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States.,Graduate School of Genome Science and Technology, The University of Tennessee, Knoxville, Knoxville, TN, United States.,Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Qiuming Yao
- Computer Science and Mathematics Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Xuan Guo
- Computer Science and Mathematics Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Alexander Crits-Christoph
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA, United States
| | - Melanie A Mayes
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - William Judson Hervey
- Naval Research Laboratory, Center for Biomolecular Science and Engineering, Washington, DC, United States
| | - Sarah L Lebeis
- Department of Microbiology, The University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Jillian F Banfield
- Department of Earth and Planetary Science, University of California, Berkeley, Berkeley, CA, United States.,Department of Environmental Science, Policy, and Management, University of California, Berkeley, Berkeley, CA, United States
| | - Gregory B Hurst
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Robert L Hettich
- Graduate School of Genome Science and Technology, The University of Tennessee, Knoxville, Knoxville, TN, United States.,Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Chongle Pan
- Computer Science and Mathematics Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States.,Graduate School of Genome Science and Technology, The University of Tennessee, Knoxville, Knoxville, TN, United States.,School of Computer Science and Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK, United States
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33
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Lucaciu R, Pelikan C, Gerner SM, Zioutis C, Köstlbacher S, Marx H, Herbold CW, Schmidt H, Rattei T. A Bioinformatics Guide to Plant Microbiome Analysis. FRONTIERS IN PLANT SCIENCE 2019; 10:1313. [PMID: 31708944 PMCID: PMC6819368 DOI: 10.3389/fpls.2019.01313] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 09/20/2019] [Indexed: 05/18/2023]
Abstract
Recent evidence for intimate relationship of plants with their microbiota shows that plants host individual and diverse microbial communities that are essential for their survival. Understanding their relatedness using genome-based and high-throughput techniques remains a hot topic in microbiome research. Molecular analysis of the plant holobiont necessitates the application of specific sampling and preparatory steps that also consider sources of unwanted information, such as soil, co-amplified plant organelles, human DNA, and other contaminations. Here, we review state-of-the-art and present practical guidelines regarding experimental and computational aspects to be considered in molecular plant-microbiome studies. We discuss sequencing and "omics" techniques with a focus on the requirements needed to adapt these methods to individual research approaches. The choice of primers and sequence databases is of utmost importance for amplicon sequencing, while the assembly and binning of shotgun metagenomic sequences is crucial to obtain quality data. We discuss specific bioinformatic workflows to overcome the limitation of genome database resources and for covering large eukaryotic genomes such as fungi. In transcriptomics, it is necessary to account for the separation of host mRNA or dual-RNAseq data. Metaproteomics approaches provide a snapshot of the protein abundances within a plant tissue which requires the knowledge of complete and well-annotated plant genomes, as well as microbial genomes. Metabolomics offers a powerful tool to detect and quantify small molecules and molecular changes at the plant-bacteria interface if the necessary requirements with regard to (secondary) metabolite databases are considered. We highlight data integration and complementarity which should help to widen our understanding of the interactions among individual players of the plant holobiont in the future.
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Affiliation(s)
| | | | | | | | | | | | | | - Hannes Schmidt
- Department of Microbiology and Ecosystem Science, University of Vienna, Vienna, Austria
| | - Thomas Rattei
- Department of Microbiology and Ecosystem Science, University of Vienna, Vienna, Austria
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34
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Adam PS, Borrel G, Gribaldo S. An archaeal origin of the Wood–Ljungdahl H4MPT branch and the emergence of bacterial methylotrophy. Nat Microbiol 2019; 4:2155-2163. [DOI: 10.1038/s41564-019-0534-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 07/08/2019] [Indexed: 12/22/2022]
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35
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Nawrocki EP, Jones TA, Eddy SR. Group I introns are widespread in archaea. Nucleic Acids Res 2019; 46:7970-7976. [PMID: 29788499 PMCID: PMC6125680 DOI: 10.1093/nar/gky414] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2018] [Accepted: 05/04/2018] [Indexed: 01/28/2023] Open
Abstract
Group I catalytic introns have been found in bacterial, viral, organellar, and some eukaryotic genomes, but not in archaea. All known archaeal introns are bulge-helix-bulge (BHB) introns, with the exception of a few group II introns. It has been proposed that BHB introns arose from extinct group I intron ancestors, much like eukaryotic spliceosomal introns are thought to have descended from group II introns. However, group I introns have little sequence conservation, making them difficult to detect with standard sequence similarity searches. Taking advantage of recent improvements in a computational homology search method that accounts for both conserved sequence and RNA secondary structure, we have identified 39 group I introns in a wide range of archaeal phyla, including examples of group I introns and BHB introns in the same host gene.
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Affiliation(s)
- Eric P Nawrocki
- National Center for Biotechnology Information, U.S. National Library of Medicine, Bethesda, MD 20894, USA
| | - Thomas A Jones
- Howard Hughes Medical Institute, Harvard University, Cambridge, USA.,Department of Molecular and Cellular Biology, Harvard University, Cambridge, USA
| | - Sean R Eddy
- Howard Hughes Medical Institute, Harvard University, Cambridge, USA.,Department of Molecular and Cellular Biology, Harvard University, Cambridge, USA.,School of Engineering and Applied Sciences, Harvard University, Cambridge, USA
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36
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Diamond S, Andeer PF, Li Z, Crits-Christoph A, Burstein D, Anantharaman K, Lane KR, Thomas BC, Pan C, Northen TR, Banfield JF. Mediterranean grassland soil C-N compound turnover is dependent on rainfall and depth, and is mediated by genomically divergent microorganisms. Nat Microbiol 2019; 4:1356-1367. [PMID: 31110364 PMCID: PMC6784897 DOI: 10.1038/s41564-019-0449-y] [Citation(s) in RCA: 88] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 04/03/2019] [Indexed: 12/15/2022]
Abstract
Soil microbial activity drives the carbon and nitrogen cycles and is an important determinant of atmospheric trace gas turnover, yet most soils are dominated by microorganisms with unknown metabolic capacities. Even Acidobacteria, among the most abundant bacteria in soil, remain poorly characterized, and functions across groups such as Verrucomicrobia, Gemmatimonadetes, Chloroflexi and Rokubacteria are understudied. Here, we have resolved 60 metagenomic and 20 proteomic data sets from a Mediterranean grassland soil ecosystem and recovered 793 near-complete microbial genomes from 18 phyla, representing around one-third of all microorganisms detected. Importantly, this enabled extensive genomics-based metabolic predictions for these communities. Acidobacteria from multiple previously unstudied classes have genomes that encode large enzyme complements for complex carbohydrate degradation. Alternatively, most microorganisms encode carbohydrate esterases that strip readily accessible methyl and acetyl groups from polymers like pectin and xylan, forming methanol and acetate, the availability of which could explain the high prevalence of C1 metabolism and acetate utilization in genomes. Microorganism abundances among samples collected at three soil depths and under natural and amended rainfall regimes indicate statistically higher associations of inorganic nitrogen metabolism and carbon degradation in deep and shallow soils, respectively. This partitioning decreased in samples under extended spring rainfall, indicating that long-term climate alteration can affect both carbon and nitrogen cycling. Overall, by leveraging natural and experimental gradients with genome-resolved metabolic profiles, we link microorganisms lacking prior genomic characterization to specific roles in complex carbon, C1, nitrate and ammonia transformations, and constrain factors that impact their distributions in soil.
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Affiliation(s)
- Spencer Diamond
- Department of Earth and Planetary Science, University of California, Berkeley, Berkeley, CA, USA
| | - Peter F Andeer
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Zhou Li
- Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | | | - David Burstein
- Department of Earth and Planetary Science, University of California, Berkeley, Berkeley, CA, USA
- School of Molecular Cell Biology and Biotechnology, Tel Aviv University, Tel Aviv, Israel
| | - Karthik Anantharaman
- Department of Earth and Planetary Science, University of California, Berkeley, Berkeley, CA, USA
- Department of Bacteriology, University of Wisconsin, Madison, WI, USA
| | - Katherine R Lane
- Department of Earth and Planetary Science, University of California, Berkeley, Berkeley, CA, USA
| | - Brian C Thomas
- Department of Earth and Planetary Science, University of California, Berkeley, Berkeley, CA, USA
| | - Chongle Pan
- Oak Ridge National Laboratory, Oak Ridge, TN, USA
- School of Computer Science and Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK, USA
| | - Trent R Northen
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Joint Genome Institute, Lawrence Berkeley National Laboratory, Walnut Creek, CA, USA
| | - Jillian F Banfield
- Department of Earth and Planetary Science, University of California, Berkeley, Berkeley, CA, USA.
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, Berkeley, CA, USA.
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Knapik K, Becerra M, González-Siso MI. Microbial diversity analysis and screening for novel xylanase enzymes from the sediment of the Lobios Hot Spring in Spain. Sci Rep 2019; 9:11195. [PMID: 31371784 PMCID: PMC6671963 DOI: 10.1038/s41598-019-47637-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 07/11/2019] [Indexed: 01/28/2023] Open
Abstract
Here, we describe the metagenome composition of a microbial community in a hot spring sediment as well as a sequence-based and function-based screening of the metagenome for identification of novel xylanases. The sediment was collected from the Lobios Hot Spring located in the province of Ourense (Spain). Environmental DNA was extracted and sequenced using Illumina technology, and a total of 3.6 Gbp of clean paired reads was produced. A taxonomic classification that was obtained by comparison to the NCBI protein nr database revealed a dominance of Bacteria (93%), followed by Archaea (6%). The most abundant bacterial phylum was Acidobacteria (25%), while Thaumarchaeota (5%) was the main archaeal phylum. Reads were assembled into contigs. Open reading frames (ORFs) predicted on these contigs were searched by BLAST against the CAZy database to retrieve xylanase encoding ORFs. A metagenomic fosmid library of approximately 150,000 clones was constructed to identify functional genes encoding thermostable xylanase enzymes. Function-based screening revealed a novel xylanase-encoding gene (XynA3), which was successfully expressed in E. coli BL21. The resulting protein (41 kDa), a member of glycoside hydrolase family 11 was purified and biochemically characterized. The highest activity was measured at 80 °C and pH 6.5. The protein was extremely thermostable and showed 94% remaining activity after incubation at 60 °C for 24 h and over 70% remaining activity after incubation at 70 °C for 24 h. Xylanolytic activity of the XynA3 enzyme was stimulated in the presence of β-mercaptoethanol, dithiothreitol and Fe3+ ions. HPLC analysis showed that XynA3 hydrolyzes xylan forming xylobiose with lower proportion of xylotriose and xylose. Specific activity of the enzyme was 9080 U/mg for oat arabinoxylan and 5080 U/mg for beechwood xylan, respectively, without cellulase activity.
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Affiliation(s)
- Kamila Knapik
- Universidade da Coruña, Grupo EXPRELA, Facultade de Ciencias, Centro de Investigacións Científicas Avanzadas (CICA), A Coruña, Spain
| | - Manuel Becerra
- Universidade da Coruña, Grupo EXPRELA, Facultade de Ciencias, Centro de Investigacións Científicas Avanzadas (CICA), A Coruña, Spain
| | - María-Isabel González-Siso
- Universidade da Coruña, Grupo EXPRELA, Facultade de Ciencias, Centro de Investigacións Científicas Avanzadas (CICA), A Coruña, Spain.
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38
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Hu D, Zang Y, Mao Y, Gao B. Identification of Molecular Markers That Are Specific to the Class Thermoleophilia. Front Microbiol 2019; 10:1185. [PMID: 31178855 PMCID: PMC6544083 DOI: 10.3389/fmicb.2019.01185] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 05/09/2019] [Indexed: 12/26/2022] Open
Abstract
The class Thermoleophilia is one of the deep-rooting lineages within the Actinobacteria phylum and metagenomic investigation of microbial diversity suggested that species associated with the class Thermoleophilia are abundant in hot spring and soil samples. However, very few species of this class have been cultivated and characterized. Our understanding of the phylogeny and taxonomy of Thermoleophilia is solely based on 16S rRNA sequence analysis of limited cultivable representatives, but no other phenotypic or genotypic characteristics are known that can clearly discriminate members of this class from the other taxonomic units within the kingdom bacteria. This study reports phylogenomic analysis for 12 sequenced members of this class and clearly resolves the interrelationship of not yet cultivated species with reconstructed genomes and known type species. Comparative genome analysis discovered 12 CSIs in different proteins and 32 CSPs that are specific to all species of this class. In addition, a large number of CSIs or CSPs were identified to be unique to certain lineages within this class. This study represents the first and most comprehensive phylogenetic analysis of the class Thermoleophilia, and the identified CSIs and CSPs provide valuable molecular markers for the identification and delineation of species belonging to this class or its subordinate taxa.
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Affiliation(s)
- Danyu Hu
- CAS Key Laboratory of Tropical Marine Bio Resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yang Zang
- CAS Key Laboratory of Tropical Marine Bio Resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yingjin Mao
- CAS Key Laboratory of Tropical Marine Bio Resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Beile Gao
- CAS Key Laboratory of Tropical Marine Bio Resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
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39
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Differences in Bacterial Diversity, Composition and Function due to Long-Term Agriculture in Soils in the Eastern Free State of South Africa. DIVERSITY 2019. [DOI: 10.3390/d11040061] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Land-use change from natural to managed agricultural ecosystems significantly impacts soil bacterial diversity and function. The Eastern Free State (EFS) is one of the most productive agricultural regions in South Africa. However, no studies aiming to understand the changes in bacterial diversity, composition and function due to land-use change in this area have been conducted. This study investigated, using high-throughput 16S rRNA gene amplicon sequencing, the effects of long-term agriculture on bacterial diversity, composition and putative function in the EFS by comparing microbiomes from lands that have been under agronomic activity for over 50 years to those from uncultivated land. Results indicate that agriculture increased bacterial diversity. Soil chemical analysis showed that land-use shifted soils from being oligotrophic to copiotrophic, which changed bacterial communities from being Actinobacteria dominated to Proteobacteria dominated. Predictive functional analysis using Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) suggested that agricultural soil was abundant in genes associated with plant fitness and plant growth promotion, while non-agricultural soil was abundant in genes related to organic matter degradation. Together, these results suggest that edaphic factors induced by long-term agriculture resulted in shifts in bacterial diversity and putative function in the EFS.
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40
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Soluble expression of Thermomicrobium roseum sarcosine oxidase and characterization of N-demethylation activity. MOLECULAR CATALYSIS 2019. [DOI: 10.1016/j.mcat.2018.12.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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41
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Guo X, Li Z, Yao Q, Mueller RS, Eng JK, Tabb DL, Hervey WJ, Pan C. Sipros Ensemble improves database searching and filtering for complex metaproteomics. Bioinformatics 2018; 34:795-802. [PMID: 29028897 PMCID: PMC6192206 DOI: 10.1093/bioinformatics/btx601] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 09/19/2017] [Indexed: 01/14/2023] Open
Abstract
Motivation Complex microbial communities can be characterized by metagenomics and metaproteomics.
However, metagenome assemblies often generate enormous, and yet incomplete, protein
databases, which undermines the identification of peptides and proteins in
metaproteomics. This challenge calls for increased discrimination of true
identifications from false identifications by database searching and filtering
algorithms in metaproteomics. Results Sipros Ensemble was developed here for metaproteomics using an ensemble approach. Three
diverse scoring functions from MyriMatch, Comet and the original Sipros were
incorporated within a single database searching engine. Supervised classification with
logistic regression was used to filter database searching results. Benchmarking with
soil and marine microbial communities demonstrated a higher number of peptide and
protein identifications by Sipros Ensemble than MyriMatch/Percolator, Comet/Percolator,
MS-GF+/Percolator, Comet & MyriMatch/iProphet and Comet & MyriMatch &
MS-GF+/iProphet. Sipros Ensemble was computationally efficient and scalable on
supercomputers. Availability and implementation Freely available under the GNU GPL license at http://sipros.omicsbio.org. Supplementary information Supplementary data are
available at Bioinformatics online.
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Affiliation(s)
- Xuan Guo
- Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, TN 37996, USA.,Computer Science and Mathematics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.,Department of Computer Science and Engineering, University of North Texas, Denton, TX 76203, USA
| | - Zhou Li
- Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, TN 37996, USA.,Computer Science and Mathematics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Qiuming Yao
- Computer Science and Mathematics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Ryan S Mueller
- Department of Microbiology, Oregon State University, Corvallis, OR 97331, USA
| | - Jimmy K Eng
- Proteomics Resource, University of Washington, Seattle, WA 98195, USA
| | - David L Tabb
- DST/NRF Centre of Excellence for Biomedical Tuberculosis Research, SAMRC Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town 7505, South Africa
| | - William Judson Hervey
- Naval Research Laboratory, Center for Bio/Molecular Science & Engineering (Code 6910), Washington, DC, 20375, USA
| | - Chongle Pan
- Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, TN 37996, USA.,Computer Science and Mathematics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
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42
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Rinta-Kanto J, Pehkonen K, Sinkko H, Tamminen M, Timonen S. Archaeaare prominent members of the prokaryotic communities colonizing common forest mushrooms. Can J Microbiol 2018; 64:716-726. [DOI: 10.1139/cjm-2018-0035] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In this study, the abundance and composition of prokaryotic communities associated with the inner tissue of fruiting bodies of Suillus bovinus, Boletus pinophilus, Cantharellus cibarius, Agaricus arvensis, Lycoperdon perlatum, and Piptoporus betulinus were analyzed using culture-independent methods. Our findings indicate that archaea and bacteria colonize the internal tissues of all investigated specimens and that archaea are prominent members of the prokaryotic community. The ratio of archaeal 16S rRNA gene copy numbers to those of bacteria was >1 in the fruiting bodies of four out of six fungal species included in the study. The largest proportion of archaeal 16S rRNA gene sequences belonged to thaumarchaeotal classes Terrestrial group, Miscellaneous Crenarchaeotic Group (MCG), and Thermoplasmata. Bacterial communities showed characteristic compositions in each fungal species. Bacterial classes Gammaproteobacteria, Actinobacteria, Bacilli, and Clostridia were prominent among communities in fruiting body tissues. Bacterial populations in each fungal species had different characteristics. The results of this study imply that fruiting body tissues are an important habitat for abundant and diverse populations of archaea and bacteria.
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Affiliation(s)
- J.M. Rinta-Kanto
- University of Helsinki, Department of Microbiology, Viikinkaari 9, 00014 Helsinki, Finland
| | - K. Pehkonen
- University of Helsinki, Department of Microbiology, Viikinkaari 9, 00014 Helsinki, Finland
| | - H. Sinkko
- University of Helsinki, Department of Microbiology, Viikinkaari 9, 00014 Helsinki, Finland
| | - M.V. Tamminen
- Department of Biology, University Hill, 20014 University of Turku, Finland
| | - S. Timonen
- University of Helsinki, Department of Microbiology, Viikinkaari 9, 00014 Helsinki, Finland
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43
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Levy A, Conway JM, Dangl JL, Woyke T. Elucidating Bacterial Gene Functions in the Plant Microbiome. Cell Host Microbe 2018; 24:475-485. [DOI: 10.1016/j.chom.2018.09.005] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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44
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Mandalakis M, Panikov NS, Polymenakou PN, Sizova MV, Stamatakis A. A simple cleanup method for the removal of humic substances from soil protein extracts using aluminum coagulation. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:23845-23856. [PMID: 29876858 DOI: 10.1007/s11356-018-2434-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2018] [Accepted: 05/28/2018] [Indexed: 06/08/2023]
Abstract
Soil proteomics, the large-scale characterization of the entire protein complement in soils, provides a promising approach for deciphering the role of microbial functioning in terrestrial ecosystems. However, the extraction of soil proteins in sufficient quantities and of adequate purity remains a challenging task mainly due to the co-extraction of interfering humic substances. Up to now, the treatment of soil extracts with liquid phenol has been the "gold standard" for reducing humics, while the NoviPure cleanup kit was recently launched as a non-toxic approach. The present study describes an alternative method for delivering high-purity proteins based on humic coagulation with trivalent aluminum ions (Al3+). Various experimental parameters were optimized individually in order to maximize protein yield and diminish co-extracted humics. The optimized method was applied on a set of soil samples with diverse physicochemical characteristics and a comparison with the other two techniques was conducted. The amount of residual humics resulting from Al3+-based method was 26 and 35% higher than that from phenol treatment and NoviPure Kit, respectively, but these differences were of marginal statistical significance. With regard to extracted proteins, the average yields of the three methods were comparable, without showing any statistically significant differences. Overall, humic coagulation with Al3+ offers comparable cleanup performance in terms of protein yield and purity, but it is less toxic and less complex than the phenol-partitioning method, whereas it is far less expensive than the NoviPure Kit. The new technique is expected to facilitate the implementation of proteomic studies in soils.
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Affiliation(s)
- Manolis Mandalakis
- Institute of Marine Biology, Biotechnology and Aquaculture, Hellenic Centre for Marine Research, 71500, Heraklion, Crete, Greece.
| | | | - Paraskevi N Polymenakou
- Institute of Marine Biology, Biotechnology and Aquaculture, Hellenic Centre for Marine Research, 71500, Heraklion, Crete, Greece
| | - Maria V Sizova
- College of Science, Northeastern University, Boston, MA, 02115, USA
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45
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Kroeger ME, Delmont TO, Eren AM, Meyer KM, Guo J, Khan K, Rodrigues JLM, Bohannan BJM, Tringe SG, Borges CD, Tiedje JM, Tsai SM, Nüsslein K. New Biological Insights Into How Deforestation in Amazonia Affects Soil Microbial Communities Using Metagenomics and Metagenome-Assembled Genomes. Front Microbiol 2018; 9:1635. [PMID: 30083144 PMCID: PMC6064768 DOI: 10.3389/fmicb.2018.01635] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 06/30/2018] [Indexed: 11/17/2022] Open
Abstract
Deforestation in the Brazilian Amazon occurs at an alarming rate, which has broad effects on global greenhouse gas emissions, carbon storage, and biogeochemical cycles. In this study, soil metagenomes and metagenome-assembled genomes (MAGs) were analyzed for alterations to microbial community composition, functional groups, and putative physiology as it related to land-use change and tropical soil. A total of 28 MAGs were assembled encompassing 10 phyla, including both dominant and rare biosphere lineages. Amazon Acidobacteria subdivision 3, Melainabacteria, Microgenomates, and Parcubacteria were found exclusively in pasture soil samples, while Candidatus Rokubacteria was predominant in the adjacent rainforest soil. These shifts in relative abundance between land-use types were supported by the different putative physiologies and life strategies employed by the taxa. This research provides unique biological insights into candidate phyla in tropical soil and how deforestation may impact the carbon cycle and affect climate change.
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Affiliation(s)
- Marie E Kroeger
- Department of Microbiology, University of Massachusetts Amherst, Amherst, MA, United States
| | - Tom O Delmont
- Department of Medicine, University of Chicago, Chicago, IL, United States
| | - A M Eren
- Department of Medicine, University of Chicago, Chicago, IL, United States.,Josephine Bay Paul Center, Marine Biological Laboratory, Woods Hole, MA, United States
| | - Kyle M Meyer
- Institute of Ecology and Evolution, University of Oregon, Eugene, OR, United States
| | - Jiarong Guo
- Center for Microbial Ecology, Michigan State University, East Lansing, MI, United States
| | - Kiran Khan
- Department of Microbiology, University of Massachusetts Amherst, Amherst, MA, United States
| | - Jorge L M Rodrigues
- Department of Land, Air, and Water Resources, University of California, Davis, Davis, CA, United States
| | - Brendan J M Bohannan
- Institute of Ecology and Evolution, University of Oregon, Eugene, OR, United States
| | | | - Clovis D Borges
- Centro de Energia Nuclear na Agricultura, University of São Paulo, Piracicaba, Brazil
| | - James M Tiedje
- Center for Microbial Ecology, Michigan State University, East Lansing, MI, United States
| | - Siu M Tsai
- Centro de Energia Nuclear na Agricultura, University of São Paulo, Piracicaba, Brazil
| | - Klaus Nüsslein
- Department of Microbiology, University of Massachusetts Amherst, Amherst, MA, United States
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46
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Sieber CMK, Probst AJ, Sharrar A, Thomas BC, Hess M, Tringe SG, Banfield JF. Recovery of genomes from metagenomes via a dereplication, aggregation and scoring strategy. Nat Microbiol 2018; 3:836-843. [PMID: 29807988 PMCID: PMC6786971 DOI: 10.1038/s41564-018-0171-1] [Citation(s) in RCA: 615] [Impact Index Per Article: 102.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Accepted: 04/27/2018] [Indexed: 11/30/2022]
Abstract
Microbial communities are critical to ecosystem function. A key objective of metagenomic studies is to analyse organism-specific metabolic pathways and reconstruct community interaction networks. This requires accurate assignment of assembled genome fragments to genomes. Existing binning methods often fail to reconstruct a reasonable number of genomes and report many bins of low quality and completeness. Furthermore, the performance of existing algorithms varies between samples and biotopes. Here, we present a dereplication, aggregation and scoring strategy, DAS Tool, that combines the strengths of a flexible set of established binning algorithms. DAS Tool applied to a constructed community generated more accurate bins than any automated method. Indeed, when applied to environmental and host-associated samples of different complexity, DAS Tool recovered substantially more near-complete genomes, including previously unreported lineages, than any single binning method alone. The ability to reconstruct many near-complete genomes from metagenomics data will greatly advance genome-centric analyses of ecosystems.
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Affiliation(s)
- Christian M K Sieber
- Department of Energy, Joint Genome Institute, Walnut Creek, CA, USA
- Department of Earth and Planetary Science, University of California, Berkeley, CA, USA
| | - Alexander J Probst
- Department of Earth and Planetary Science, University of California, Berkeley, CA, USA
| | - Allison Sharrar
- Department of Earth and Planetary Science, University of California, Berkeley, CA, USA
| | - Brian C Thomas
- Department of Earth and Planetary Science, University of California, Berkeley, CA, USA
| | - Matthias Hess
- Department of Animal Science, University of California, Davis, CA, USA
| | - Susannah G Tringe
- Department of Energy, Joint Genome Institute, Walnut Creek, CA, USA.
| | - Jillian F Banfield
- Department of Earth and Planetary Science, University of California, Berkeley, CA, USA.
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47
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Novel soil bacteria possess diverse genes for secondary metabolite biosynthesis. Nature 2018; 558:440-444. [PMID: 29899444 DOI: 10.1038/s41586-018-0207-y] [Citation(s) in RCA: 206] [Impact Index Per Article: 34.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Accepted: 05/02/2018] [Indexed: 11/08/2022]
Abstract
In soil ecosystems, microorganisms produce diverse secondary metabolites such as antibiotics, antifungals and siderophores that mediate communication, competition and interactions with other organisms and the environment1,2. Most known antibiotics are derived from a few culturable microbial taxa 3 , and the biosynthetic potential of the vast majority of bacteria in soil has rarely been investigated 4 . Here we reconstruct hundreds of near-complete genomes from grassland soil metagenomes and identify microorganisms from previously understudied phyla that encode diverse polyketide and nonribosomal peptide biosynthetic gene clusters that are divergent from well-studied clusters. These biosynthetic loci are encoded by newly identified members of the Acidobacteria, Verrucomicobia and Gemmatimonadetes, and the candidate phylum Rokubacteria. Bacteria from these groups are highly abundant in soils5-7, but have not previously been genomically linked to secondary metabolite production with confidence. In particular, large numbers of biosynthetic genes were characterized in newly identified members of the Acidobacteria, which is the most abundant bacterial phylum across soil biomes 5 . We identify two acidobacterial genomes from divergent lineages, each of which encodes an unusually large repertoire of biosynthetic genes with up to fifteen large polyketide and nonribosomal peptide biosynthetic loci per genome. To track gene expression of genes encoding polyketide synthases and nonribosomal peptide synthetases in the soil ecosystem that we studied, we sampled 120 time points in a microcosm manipulation experiment and, using metatranscriptomics, found that gene clusters were differentially co-expressed in response to environmental perturbations. Transcriptional co-expression networks for specific organisms associated biosynthetic genes with two-component systems, transcriptional activation, putative antimicrobial resistance and iron regulation, linking metabolite biosynthesis to processes of environmental sensing and ecological competition. We conclude that the biosynthetic potential of abundant and phylogenetically diverse soil microorganisms has previously been underestimated. These organisms may represent a source of natural products that can address needs for new antibiotics and other pharmaceutical compounds.
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48
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Castelle CJ, Banfield JF. Major New Microbial Groups Expand Diversity and Alter our Understanding of the Tree of Life. Cell 2018. [DOI: 10.1016/j.cell.2018.02.016] [Citation(s) in RCA: 315] [Impact Index Per Article: 52.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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49
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Jaeger N, Besaury L, Kröber E, Delort AM, Greule M, Lenhart K, Nadalig T, Vuilleumier S, Amato P, Kolb S, Bringel F, Keppler F. Chloromethane Degradation in Soils: A Combined Microbial and Two-Dimensional Stable Isotope Approach. JOURNAL OF ENVIRONMENTAL QUALITY 2018; 47:254-262. [PMID: 29634809 DOI: 10.2134/jeq2017.09.0358] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Chloromethane (CHCl, methyl chloride) is the most abundant volatile halocarbon in the atmosphere and involved in stratospheric ozone depletion. The global CHCl budget, and especially the CHCl sink from microbial degradation in soil, still involves large uncertainties. These may potentially be resolved by a combination of stable isotope analysis and bacterial diversity studies. We determined the stable isotope fractionation of CHCl hydrogen and carbon and investigated bacterial diversity during CHCl degradation in three soils with different properties (forest, grassland, and agricultural soils) and at different temperatures and headspace mixing ratios of CHCl. The extent of chloromethane degradation decreased in the order forest > grassland > agricultural soil. Rates ranged from 0.7 to 2.5 μg g dry wt. d for forest soil, from 0.1 to 0.9 μg g dry wt. d for grassland soil, and from 0.1 to 0.4 μg g dry wt. d for agricultural soil and increased with increasing temperature and CHCl supplementation. The measured mean stable hydrogen enrichment factor of CHCl of -50 ± 13‰ was unaffected by temperature, mixing ratio, or soil type. In contrast, the stable carbon enrichment factor depended on CHCl degradation rates and ranged from -38 to -11‰. Bacterial community composition correlated with soil properties was independent from CHCl degradation or isotope enrichment. Nevertheless, increased abundance after CHCl incubation was observed in 21 bacterial operational taxonomical units (OTUs at the 97% 16S RNA sequence identity level). This suggests that some of these bacterial taxa, although not previously associated with CHCl degradation, may play a role in the microbial CHCl sink in soil.
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Chistoserdova L, Kalyuzhnaya MG. Current Trends in Methylotrophy. Trends Microbiol 2018; 26:703-714. [PMID: 29471983 DOI: 10.1016/j.tim.2018.01.011] [Citation(s) in RCA: 83] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Revised: 01/18/2018] [Accepted: 01/30/2018] [Indexed: 11/26/2022]
Abstract
Methylotrophy is a field of study dealing with microorganisms capable of utilization of compounds devoid of carbon-carbon bonds (C1 compounds). In this review, we highlight several emerging trends in methylotrophy. First, we discuss the significance of the recent discovery of lanthanide-dependent alcohol dehydrogenases for understanding both the occurrence and the distribution of methylotrophy functions among bacteria, and then we discuss the newly appreciated role of lanthanides in biology. Next, we describe the detection of other methylotrophy pathways across novel bacterial taxa and insights into the evolution of methylotrophy. Further, data are presented on the occurrence and activity of aerobic methylotrophs in hypoxic and anoxic environments, questioning the prior assumptions on niche separation of aerobic and anaerobic methylotrophy. The concept of communal function in aerobic methane oxidation is also briefly discussed. Finally, we review recent research in engineering methylotrophs for biotechnological applications as well as recent progress in engineering synthetic methylotrophy.
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