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Wang Y, Zhang Y, Cui Q, Feng Y, Xuan J. Composition of Lignocellulose Hydrolysate in Different Biorefinery Strategies: Nutrients and Inhibitors. Molecules 2024; 29:2275. [PMID: 38792135 PMCID: PMC11123716 DOI: 10.3390/molecules29102275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Revised: 05/06/2024] [Accepted: 05/09/2024] [Indexed: 05/26/2024] Open
Abstract
The hydrolysis and biotransformation of lignocellulose, i.e., biorefinery, can provide human beings with biofuels, bio-based chemicals, and materials, and is an important technology to solve the fossil energy crisis and promote global sustainable development. Biorefinery involves steps such as pretreatment, saccharification, and fermentation, and researchers have developed a variety of biorefinery strategies to optimize the process and reduce process costs in recent years. Lignocellulosic hydrolysates are platforms that connect the saccharification process and downstream fermentation. The hydrolysate composition is closely related to biomass raw materials, the pretreatment process, and the choice of biorefining strategies, and provides not only nutrients but also possible inhibitors for downstream fermentation. In this review, we summarized the effects of each stage of lignocellulosic biorefinery on nutrients and possible inhibitors, analyzed the huge differences in nutrient retention and inhibitor generation among various biorefinery strategies, and emphasized that all steps in lignocellulose biorefinery need to be considered comprehensively to achieve maximum nutrient retention and optimal control of inhibitors at low cost, to provide a reference for the development of biomass energy and chemicals.
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Affiliation(s)
- Yilan Wang
- Department of Bioscience and Bioengineering, School of Chemistry and Biological Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Beijing 100083, China
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Shandong Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 189 Songling Road, Qingdao 266101, China
| | - Yuedong Zhang
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Shandong Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 189 Songling Road, Qingdao 266101, China
- Shandong Energy Institute, 189 Songling Road, Qingdao 266101, China
- Qingdao New Energy Shandong Laboratory, 189 Songling Road, Qingdao 266101, China
| | - Qiu Cui
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Shandong Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 189 Songling Road, Qingdao 266101, China
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Yingang Feng
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Shandong Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 189 Songling Road, Qingdao 266101, China
- Shandong Energy Institute, 189 Songling Road, Qingdao 266101, China
- Qingdao New Energy Shandong Laboratory, 189 Songling Road, Qingdao 266101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jinsong Xuan
- Department of Bioscience and Bioengineering, School of Chemistry and Biological Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Beijing 100083, China
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2
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Zhou SP, Ke X, Jin LQ, Xue YP, Zheng YG. Sustainable management and valorization of biomass wastes using synthetic microbial consortia. BIORESOURCE TECHNOLOGY 2024; 395:130391. [PMID: 38307483 DOI: 10.1016/j.biortech.2024.130391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 01/23/2024] [Accepted: 01/25/2024] [Indexed: 02/04/2024]
Abstract
In response to the persistent expansion of global resource demands, considerable attention has been directed toward the synthetic microbial consortia (SMC) within the domain of microbial engineering, aiming to address the sustainable management and valorization of biomass wastes. This comprehensive review systematically encapsulates the most recent advancements in research and technological applications concerning the utilization of SMC for biomass waste treatment. The construction strategies of SMC are briefly outlined, and the diverse applications of SMC in biomass wastes treatment are explored, with particular emphasis on its potential advantages in waste degradation, hazardous substances control, and high value-added products conversion. Finally, recommendations for the future development of SMC technology are proposed, and prospects for its sustainable application are discussed.
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Affiliation(s)
- Shi-Peng Zhou
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, China
| | - Xia Ke
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, China
| | - Li-Qun Jin
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, China
| | - Ya-Ping Xue
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, China.
| | - Yu-Guo Zheng
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, China
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3
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Kurt F, Leventhal GE, Spalinger MR, Anthamatten L, Rogalla von Bieberstein P, Menzi C, Reichlin M, Meola M, Rosenthal F, Rogler G, Lacroix C, de Wouters T. Co-cultivation is a powerful approach to produce a robust functionally designed synthetic consortium as a live biotherapeutic product (LBP). Gut Microbes 2023; 15:2177486. [PMID: 36794804 PMCID: PMC9980632 DOI: 10.1080/19490976.2023.2177486] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 01/31/2023] [Indexed: 02/17/2023] Open
Abstract
The success of fecal microbiota transplants (FMT) has provided the necessary proof-of-concept for microbiome therapeutics. Yet, feces-based therapies have many associated risks and uncertainties, and hence defined microbial consortia that modify the microbiome in a targeted manner have emerged as a promising safer alternative to FMT. The development of such live biotherapeutic products has important challenges, including the selection of appropriate strains and the controlled production of the consortia at scale. Here, we report on an ecology- and biotechnology-based approach to microbial consortium construction that overcomes these issues. We selected nine strains that form a consortium to emulate the central metabolic pathways of carbohydrate fermentation in the healthy human gut microbiota. Continuous co-culturing of the bacteria produces a stable and reproducible consortium whose growth and metabolic activity are distinct from an equivalent mix of individually cultured strains. Further, we showed that our function-based consortium is as effective as FMT in counteracting dysbiosis in a dextran sodium sulfate mouse model of acute colitis, while an equivalent mix of strains failed to match FMT. Finally, we showed robustness and general applicability of our approach by designing and producing additional stable consortia of controlled composition. We propose that combining a bottom-up functional design with continuous co-cultivation is a powerful strategy to produce robust functionally designed synthetic consortia for therapeutic use.
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Affiliation(s)
- Fabienne Kurt
- PharmaBiome AG, Schlieren, Switzerland
- Laboratory of Food Biotechnology, Institute of Food, Nutrition and Health, ETH Zurich, Zurich, Switzerland
| | | | - Marianne Rebecca Spalinger
- Department of Gastroenterology and Hepatology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Laura Anthamatten
- PharmaBiome AG, Schlieren, Switzerland
- Laboratory of Food Biotechnology, Institute of Food, Nutrition and Health, ETH Zurich, Zurich, Switzerland
| | | | | | | | | | | | - Gerhard Rogler
- Department of Gastroenterology and Hepatology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Christophe Lacroix
- Laboratory of Food Biotechnology, Institute of Food, Nutrition and Health, ETH Zurich, Zurich, Switzerland
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4
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Lin L. Bottom-up synthetic ecology study of microbial consortia to enhance lignocellulose bioconversion. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2022; 15:14. [PMID: 35418100 PMCID: PMC8822760 DOI: 10.1186/s13068-022-02113-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 01/28/2022] [Indexed: 01/21/2023]
Abstract
Lignocellulose is the most abundant organic carbon polymer on the earth. Its decomposition and conversion greatly impact the global carbon cycle. Furthermore, it provides feedstock for sustainable fuel and other value-added products. However, it continues to be underutilized, due to its highly recalcitrant and heterogeneric structure. Microorganisms, which have evolved versatile pathways to convert lignocellulose, undoubtedly are at the heart of lignocellulose conversion. Numerous studies that have reported successful metabolic engineering of individual strains to improve biological lignin valorization. Meanwhile, the bottleneck of single strain modification is becoming increasingly urgent in the conversion of complex substrates. Alternatively, increased attention has been paid to microbial consortia, as they show advantages over pure cultures, e.g., high efficiency and robustness. Here, we first review recent developments in microbial communities for lignocellulose bioconversion. Furthermore, the emerging area of synthetic ecology, which is an integration of synthetic biology, ecology, and computational biology, provides an opportunity for the bottom-up construction of microbial consortia. Then, we review different modes of microbial interaction and their molecular mechanisms, and discuss considerations of how to employ these interactions to construct synthetic consortia via synthetic ecology, as well as highlight emerging trends in engineering microbial communities for lignocellulose bioconversion.
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Affiliation(s)
- Lu Lin
- Institute of Marine Science and Technology, Shandong University, Qingdao, 266237, Shandong, China.
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5
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Kubis MR, Holwerda EK, Lynd LR. Declining carbohydrate solubilization with increasing solids loading during fermentation of cellulosic feedstocks by Clostridium thermocellum: documentation and diagnostic tests. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2022; 15:12. [PMID: 35418299 PMCID: PMC8817502 DOI: 10.1186/s13068-022-02110-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Accepted: 01/15/2022] [Indexed: 12/31/2022]
Abstract
Background For economically viable 2nd generation biofuels, processing of high solid lignocellulosic substrate concentrations is a necessity. The cellulolytic thermophilic anaerobe Clostridium thermocellum is one of the most effective biocatalysts for solubilization of carbohydrate harbored in lignocellulose. This study aims to document the solubilization performance of Clostridium thermocellum at increasing solids concentrations for two lignocellulosic feedstocks, corn stover and switchgrass, and explore potential effectors of solubilization performance. Results Monocultures of Clostridium thermocellum demonstrated high levels of carbohydrate solubilization for both unpretreated corn stover and switchgrass. However, fractional carbohydrate solubilization decreases with increasing solid loadings. Fermentation of model insoluble substrate (cellulose) in the presence of high solids lignocellulosic spent broth is temporarily affected but not model soluble substrate (cellobiose) fermentations. Mid-fermentation addition of cells (C. thermocellum) or model substrates did not significantly enhance overall corn stover solubilization loaded at 80 g/L, however cultures utilized the model substrates in the presence of high concentrations of corn stover. An increase in corn stover solubilization was observed when water was added, effectively diluting the solids concentration mid-fermentation. Introduction of a hemicellulose-utilizing coculture partner, Thermoanaerobacterium thermosaccharolyticum, increased the fractional carbohydrate solubilization at both high and low solid loadings. Residual solubilized carbohydrates diminished significantly in the presence of T. thermosaccharolyticum compared to monocultures of C. thermocellum, yet a small fraction of solubilized oligosaccharides of both C5 and C6 sugars remained unutilized. Conclusion Diminishing fractional carbohydrate solubilization with increasing substrate loading was observed for C. thermocellum-mediated solubilization and fermentation of unpretreated lignocellulose feedstocks. Results of experiments involving spent broth addition do not support a major role for inhibitors present in the liquid phase. Mid-fermentation addition experiments confirm that C. thermocellum and its enzymes remain capable of converting model substrates during the middle of high solids lignocellulose fermentation. An increase in fractional carbohydrate solubilization was made possible by (1) mid-fermentation solid loading dilutions and (2) coculturing C. thermocellum with T. thermosaccharolyticum, which ferments solubilized hemicellulose. Incomplete utilization of solubilized carbohydrates suggests that a small fraction of the carbohydrates is unaffected by the extracellular carbohydrate-active enzymes present in the culture. Supplementary Information The online version contains supplementary material available at 10.1186/s13068-022-02110-4.
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Affiliation(s)
- Matthew R Kubis
- Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, NH, 03755, USA.,The Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Evert K Holwerda
- Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, NH, 03755, USA. .,The Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
| | - Lee R Lynd
- Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, NH, 03755, USA.,The Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
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6
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Biorefinery Gets Hot: Thermophilic Enzymes and Microorganisms for Second-Generation Bioethanol Production. Processes (Basel) 2021. [DOI: 10.3390/pr9091583] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
To mitigate the current global energy and the environmental crisis, biofuels such as bioethanol have progressively gained attention from both scientific and industrial perspectives. However, at present, commercialized bioethanol is mainly derived from edible crops, thus raising serious concerns given its competition with feed production. For this reason, lignocellulosic biomasses (LCBs) have been recognized as important alternatives for bioethanol production. Because LCBs supply is sustainable, abundant, widespread, and cheap, LCBs-derived bioethanol currently represents one of the most viable solutions to meet the global demand for liquid fuel. However, the cost-effective conversion of LCBs into ethanol remains a challenge and its implementation has been hampered by several bottlenecks that must still be tackled. Among other factors related to the challenging and variable nature of LCBs, we highlight: (i) energy-demanding pretreatments, (ii) expensive hydrolytic enzyme blends, and (iii) the need for microorganisms that can ferment mixed sugars. In this regard, thermophiles represent valuable tools to overcome some of these limitations. Thus, the aim of this review is to provide an overview of the state-of-the-art technologies involved, such as the use of thermophilic enzymes and microorganisms in industrial-relevant conditions, and to propose possible means to implement thermophiles into second-generation ethanol biorefineries that are already in operation.
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7
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Popova LI, Bahl H, Egorova MA, Leont’eva MR, Netrusov AI, Tsavkelova EA. Isolation of Cellulose-Degrading Thermoanaerobacterium Strains from Thermophilic Methanogenic Microbial Communities. Microbiology (Reading) 2021. [DOI: 10.1134/s0026261721020090] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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8
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Froese AG, Sparling R. Cross-feeding and wheat straw extractives enhance growth of Clostridium thermocellum-containing co-cultures for consolidated bioprocessing. Bioprocess Biosyst Eng 2021; 44:819-830. [PMID: 33392746 DOI: 10.1007/s00449-020-02490-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 11/24/2020] [Indexed: 01/19/2023]
Abstract
Co-cultures consisting of three thermophilic and lignocellulolytic bacteria, namely Clostridium thermocellum, C. stercorarium, and Thermoanaerobacter thermohydrosulfuricus, degrade lignocellulosic material in a synergistic manner. When cultured in a defined minimal medium two of the members appeared to be auxotrophic and unable to grow, but the growth of all species was observed in all co-culture combinations, indicating cross-feeding of unidentified growth factors between the members. Growth factors also appeared to be present in water-soluble extractives obtained from wheat straw, allowing for the growth of the auxotrophic monocultures in the defined minimal medium. Cell enumeration during growth on wheat straw in this medium revealed different growth profiles of the members that varied between the co-cultures. End-product profiles also varied substantially between the cultures, with significantly higher ethanol production in all co-cultures compared to the mono-cultures. Understanding interactions between co-culture members, and the additional nutrients provided by lignocellulosic substrates, will aid us in consolidated bioprocessing design.
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Affiliation(s)
- Alan G Froese
- Department of Microbiology, University of Manitoba, 213 Buller Building, Winnipeg, MB, R3T 2N2, Canada
| | - Richard Sparling
- Department of Microbiology, University of Manitoba, 213 Buller Building, Winnipeg, MB, R3T 2N2, Canada.
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9
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Du Y, Zou W, Zhang K, Ye G, Yang J. Advances and Applications of Clostridium Co-culture Systems in Biotechnology. Front Microbiol 2020; 11:560223. [PMID: 33312166 PMCID: PMC7701477 DOI: 10.3389/fmicb.2020.560223] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 10/20/2020] [Indexed: 01/09/2023] Open
Abstract
Clostridium spp. are important microorganisms that can degrade complex biomasses such as lignocellulose, which is a widespread and renewable natural resource. Co-culturing Clostridium spp. and other microorganisms is considered to be a promising strategy for utilizing renewable feed stocks and has been widely used in biotechnology to produce bio-fuels and bio-solvents. In this review, we summarize recent progress on the Clostridium co-culture system, including system unique advantages, composition, products, and interaction mechanisms. In addition, biochemical regulation and genetic modifications used to improve the Clostridium co-culture system are also summarized. Finally, future prospects for Clostridium co-culture systems are discussed in light of recent progress, challenges, and trends.
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Affiliation(s)
- Yuanfen Du
- College of Bioengineering, Sichuan University of Science and Engineering, Yibin, China.,Research Laboratory of Baijiu Resource Microorgannisms and Big Data, Sichuan University of Science and Engineering, Yibin, China
| | - Wei Zou
- College of Bioengineering, Sichuan University of Science and Engineering, Yibin, China.,Research Laboratory of Baijiu Resource Microorgannisms and Big Data, Sichuan University of Science and Engineering, Yibin, China
| | - Kaizheng Zhang
- College of Bioengineering, Sichuan University of Science and Engineering, Yibin, China
| | - Guangbin Ye
- College of Bioengineering, Sichuan University of Science and Engineering, Yibin, China
| | - Jiangang Yang
- College of Bioengineering, Sichuan University of Science and Engineering, Yibin, China
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10
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Rettenmaier R, Schneider M, Munk B, Lebuhn M, Jünemann S, Sczyrba A, Maus I, Zverlov V, Liebl W. Importance of Defluviitalea raffinosedens for Hydrolytic Biomass Degradation in Co-Culture with Hungateiclostridium thermocellum. Microorganisms 2020; 8:E915. [PMID: 32560349 PMCID: PMC7355431 DOI: 10.3390/microorganisms8060915] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 06/06/2020] [Accepted: 06/11/2020] [Indexed: 01/02/2023] Open
Abstract
Bacterial hydrolysis of polysaccharides is an important step for the production of sustainable energy, for example during the conversion of plant biomass to methane-rich biogas. Previously, Hungateiclostridium thermocellum was identified as cellulolytic key player in thermophilic biogas microbiomes with a great frequency as an accompanying organism. The aim of this study was to physiologically characterize a recently isolated co-culture of H. thermocellum and the saccharolytic bacterium Defluviitalea raffinosedens from a laboratory-scale biogas fermenter. The characterization focused on cellulose breakdown by applying the measurement of cellulose hydrolysis, production of metabolites, and the activity of secreted enzymes. Substrate degradation and the production of volatile metabolites was considerably enhanced when both organisms acted synergistically. The metabolic properties of H. thermocellum have been studied well in the past. To predict the role of D. raffinosedens in this bacterial duet, the genome of D. raffinosedens was sequenced for the first time. Concomitantly, to deduce the prevalence of D. raffinosedens in anaerobic digestion, taxonomic composition and transcriptional activity of different biogas microbiomes were analyzed in detail. Defluviitalea was abundant and metabolically active in reactor operating at highly efficient process conditions, supporting the importance of this organism for the hydrolysis of the raw substrate.
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Affiliation(s)
- Regina Rettenmaier
- Chair of Microbiology, Technical University of Munich, Emil-Ramann-Str. 4, 85354 Freising, Germany; (R.R.); (M.S.); (W.L.)
| | - Martina Schneider
- Chair of Microbiology, Technical University of Munich, Emil-Ramann-Str. 4, 85354 Freising, Germany; (R.R.); (M.S.); (W.L.)
| | - Bernhard Munk
- Department for Quality Assurance and Analytics, Bavarian State Research Center for Agriculture, Lange Point 6, 85354 Freising, Germany; (B.M.); (M.L.)
| | - Michael Lebuhn
- Department for Quality Assurance and Analytics, Bavarian State Research Center for Agriculture, Lange Point 6, 85354 Freising, Germany; (B.M.); (M.L.)
| | - Sebastian Jünemann
- Center for Biotechnology (CeBiTec), Universitätsstr. 27, 33615 Bielefeld, Germany;
- Faculty of Technology, Bielefeld University, Universitätsstr. 25, 33615 Bielefeld, Germany;
| | - Alexander Sczyrba
- Faculty of Technology, Bielefeld University, Universitätsstr. 25, 33615 Bielefeld, Germany;
| | - Irena Maus
- Center for Biotechnology (CeBiTec), Universitätsstr. 27, 33615 Bielefeld, Germany;
| | - Vladimir Zverlov
- Chair of Microbiology, Technical University of Munich, Emil-Ramann-Str. 4, 85354 Freising, Germany; (R.R.); (M.S.); (W.L.)
- Institute of Molecular Genetics, RAS, Kurchatov Sq. 2, 123182 Moscow, Russia
| | - Wolfgang Liebl
- Chair of Microbiology, Technical University of Munich, Emil-Ramann-Str. 4, 85354 Freising, Germany; (R.R.); (M.S.); (W.L.)
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Wang B, Zheng X, Zhang H, Xiao F, Gu H, Zhang K, He Z, Liu X, Yan Q. Bacterial community responses to tourism development in the Xixi National Wetland Park, China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 720:137570. [PMID: 32135287 DOI: 10.1016/j.scitotenv.2020.137570] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2020] [Revised: 02/23/2020] [Accepted: 02/24/2020] [Indexed: 06/10/2023]
Abstract
A large number of urban wetland parks have been established, but knowledge about the effects of tourism development on the microbial diversity and ecosystem functioning remains limited. This study aimed to clarify the responses of bacterial communities to tourism development targeted the Xixi National Wetland Park, China. By analyzing the diversity, composition, assembly pattern, and environmental drivers of bacterial communities, we found that tourism development considerably affected the water quality, which further decreased the α-diversity but increased the β-diversity in open areas for landscaping and recreation. Specifically, there was higher Simpson dissimilarity across functional wetland areas, indicating that species replacement mainly explained β-diversity patterns of bacterial communities. RDA analysis and ecological processes quantification further suggested that TOC and TC were the major factors in the open areas driving bacterial communities in water and sediment, respectively. Also, typical anti-disturbance taxa (Gammaproteobacteria) and potential pathogens (Bacillus) were enriched in the wetlands under more anthropogenic disturbances. Findings of the present study highlighted the effects of tourism development on bacterial communities resulted in obvious spatial variation in the Xixi National Wetland Park. This study gives us useful information for ecological assessments of urban wetlands, and further can provide references in making appropriate strategies to manage wetland ecosystems.
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Affiliation(s)
- Binhao Wang
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou 510006, China
| | - Xiafei Zheng
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou 510006, China
| | - Hangjun Zhang
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
| | - Fanshu Xiao
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou 510006, China
| | - Hang Gu
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou 510006, China
| | - Keke Zhang
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou 510006, China
| | - Zhili He
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou 510006, China; College of Agronomy, Hunan Agricultural University, Changsha 410128, China
| | - Xiang Liu
- Hangzhou Xixi National Wetland Park Research Center for Ecological Science, Hangzhou 310030, China
| | - Qingyun Yan
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou 510006, China.
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12
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Mazzoli R, Olson D. Clostridium thermocellum: A microbial platform for high-value chemical production from lignocellulose. ADVANCES IN APPLIED MICROBIOLOGY 2020; 113:111-161. [PMID: 32948265 DOI: 10.1016/bs.aambs.2020.07.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Second generation biorefining, namely fermentation processes based on lignocellulosic feedstocks, has attracted tremendous interest (owing to the large availability and low cost of this biomass) as a strategy to produce biofuels and commodity chemicals that is an alternative to oil refining. However, the innate recalcitrance of lignocellulose has slowed progress toward economically viable processes. Consolidated bioprocessing (CBP), i.e., single-step fermentation of lignocellulose may dramatically reduce the current costs of 2nd generation biorefining. Metabolic engineering has been used as a tool to develop improved microbial strains supporting CBP. Clostridium thermocellum is among the most efficient cellulose degraders isolated so far and one of the most promising host organisms for application of CBP. The development of efficient and reliable genetic tools has allowed significant progress in metabolic engineering of this strain aimed at expanding the panel of growth substrates and improving the production of a number of commodity chemicals of industrial interest such as ethanol, butanol, isobutanol, isobutyl acetate and lactic acid. The present review aims to summarize recent developments in metabolic engineering of this organism which currently represents a reference model for the development of biocatalysts for 2nd generation biorefining.
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13
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Wang F, Wang M, Zhao Q, Niu K, Liu S, He D, Liu Y, Xu S, Fang X. Exploring the Relationship Between Clostridium thermocellum JN4 and Thermoanaerobacterium thermosaccharolyticum GD17. Front Microbiol 2019; 10:2035. [PMID: 31551972 PMCID: PMC6746925 DOI: 10.3389/fmicb.2019.02035] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 08/19/2019] [Indexed: 11/13/2022] Open
Abstract
Characterizing and engineering microbial communities for lignocellulosic biofuel production has received widespread attention. Previous research has established that Clostridium thermocellum JN4 and Thermoanaerobacterium thermosaccharolyticum GD17 coculture significantly improves overall cellulosic biofuel production efficiency. Here, we investigated this interaction and revealed the mechanism underlying the improved efficiency observed. In contrast to the previously reported mutualistic relationship, a harmful effect toward C. thermocellum JN4 was observed in these microbial consortia. Although T. thermosaccharolyticum GD17 relieves the carbon catabolite repression of C. thermocellum JN4 regarding obtaining more cellobiose or glucose released from lignocellulose, T. thermosaccharolyticum GD17 significantly hampers the growth of C. thermocellum JN4 in coculture. The increased formation of end products is due to the strong competitive metabolic advantage of T. thermosaccharolyticum GD17 over C. thermocellum JN4 in the conversion of glucose or cellobiose into final products. The possibility of controlling and rebalancing these microbial consortia to modulate cellulose degradation was achieved by adding T. thermosaccharolyticum GD17 stimulants into the system. As cellulolytic bacteria are usually at a metabolic disadvantage, these discoveries may apply to a large proportion of cellulosic biofuel-producing microbial consortia. These findings provide a reference for engineering efficient and modular microbial consortia for modulating cellulosic conversion.
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Affiliation(s)
- Fangzhong Wang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China.,Center for Biosafety Research and Strategy, Tianjin University, Tianjin, China
| | - Mingyu Wang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Qi Zhao
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Kangle Niu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Shasha Liu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Didi He
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Yan Liu
- College of Life Science, Qufu Normal University, Qufu, China
| | - Shiping Xu
- School of Environmental Science and Engineering, Shandong University, Qingdao, China
| | - Xu Fang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
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Jiang Y, Wu R, Zhou J, He A, Xu J, Xin F, Zhang W, Ma J, Jiang M, Dong W. Recent advances of biofuels and biochemicals production from sustainable resources using co-cultivation systems. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:155. [PMID: 31285755 PMCID: PMC6588928 DOI: 10.1186/s13068-019-1495-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 06/11/2019] [Indexed: 05/09/2023]
Abstract
Microbial communities are ubiquitous in nature and exhibit several attractive features, such as sophisticated metabolic capabilities and strong environment robustness. Inspired by the advantages of natural microbial consortia, diverse artificial co-cultivation systems have been metabolically constructed for biofuels, chemicals and natural products production. In these co-cultivation systems, especially genetic engineering ones can reduce the metabolic burden caused by the complex of metabolic pathway through labor division, and improve the target product production significantly. This review summarized the most up-to-dated co-cultivation systems used for biofuels, chemicals and nature products production. In addition, major challenges associated with co-cultivation systems are also presented and discussed for meeting further industrial demands.
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Affiliation(s)
- Yujia Jiang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211800 People’s Republic of China
| | - Ruofan Wu
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211800 People’s Republic of China
| | - Jie Zhou
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211800 People’s Republic of China
- Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, 211800 People’s Republic of China
| | - Aiyong He
- Jiangsu Key Laboratory for Biomass-based Energy and Enzyme Technology, Huaiyin Normal University, Huaian, 223300 People’s Republic of China
| | - Jiaxing Xu
- Jiangsu Key Laboratory for Biomass-based Energy and Enzyme Technology, Huaiyin Normal University, Huaian, 223300 People’s Republic of China
| | - Fengxue Xin
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211800 People’s Republic of China
- Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, 211800 People’s Republic of China
| | - Wenming Zhang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211800 People’s Republic of China
- Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, 211800 People’s Republic of China
| | - Jiangfeng Ma
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211800 People’s Republic of China
- Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, 211800 People’s Republic of China
| | - Min Jiang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211800 People’s Republic of China
- Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, 211800 People’s Republic of China
| | - Weiliang Dong
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211800 People’s Republic of China
- Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, 211800 People’s Republic of China
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15
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Suleiman M, Klippel B, Busch P, Schäfers C, Moccand C, Bel-Rhlid R, Palzer S, Antranikian G. Enrichment of anaerobic heterotrophic thermophiles from four Azorean hot springs revealed different community composition and genera abundances using recalcitrant substrates. Extremophiles 2019; 23:277-281. [PMID: 30741334 DOI: 10.1007/s00792-019-01079-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Accepted: 02/03/2019] [Indexed: 11/26/2022]
Abstract
DGGE analysis combined with a metagenomic approach was used to get insights into heterotrophic anoxic enrichment cultures of four hot springs of Vale das Furnas, Portugal, using the recalcitrant substrate spent coffee ground (SCG). Parallel enrichment cultures were performed using the major components of spent coffee ground, namely arabinogalactan, galactomannan, cellulose, and proteins. DGGE revealed that heterotrophic thermophilic bacteria are highly abundant in the hydrothermal springs and significant differences in community composition depending on the substrate were observed. DNA, isolated from enrichment cultures of different locations that were grown on the same substrate were pooled, and the respective metagenomes were analyzed. Results indicated that cultures grown on recalcitrant substrate SCG consists of a totally different thermophilic community, dominated by Dictyoglomus. Enrichments with galactomannan and arabinogalactan were dominated by Thermodesulfovibrio, while cultures with casein and cellulose were dominated by Thermus. This study indicates the high potential of thermophilic bacteria degrading recalcitrant substrate such as SCG and furthermore how the accessibility to complex polymers shapes the bacterial community.
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Affiliation(s)
- Marcel Suleiman
- Institute of Technical Microbiology, Hamburg University of Technology, Hamburg, Germany
| | - Barbara Klippel
- Institute of Technical Microbiology, Hamburg University of Technology, Hamburg, Germany
| | - Philip Busch
- Institute of Technical Microbiology, Hamburg University of Technology, Hamburg, Germany
| | - Christian Schäfers
- Institute of Technical Microbiology, Hamburg University of Technology, Hamburg, Germany
| | | | | | | | - Garabed Antranikian
- Institute of Technical Microbiology, Hamburg University of Technology, Hamburg, Germany.
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16
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Roell GW, Zha J, Carr RR, Koffas MA, Fong SS, Tang YJ. Engineering microbial consortia by division of labor. Microb Cell Fact 2019; 18:35. [PMID: 30736778 PMCID: PMC6368712 DOI: 10.1186/s12934-019-1083-3] [Citation(s) in RCA: 128] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 01/31/2019] [Indexed: 12/22/2022] Open
Abstract
During microbial applications, metabolic burdens can lead to a significant drop in cell performance. Novel synthetic biology tools or multi-step bioprocessing (e.g., fermentation followed by chemical conversions) are therefore needed to avoid compromised biochemical productivity from over-burdened cells. A possible solution to address metabolic burden is Division of Labor (DoL) via natural and synthetic microbial consortia. In particular, consolidated bioprocesses and metabolic cooperation for detoxification or cross feeding (e.g., vitamin C fermentation) have shown numerous successes in industrial level applications. However, distributing a metabolic pathway among proper hosts remains an engineering conundrum due to several challenges: complex subpopulation dynamics/interactions with a short time-window for stable production, suboptimal cultivation of microbial communities, proliferation of cheaters or low-producers, intermediate metabolite dilution, transport barriers between species, and breaks in metabolite channeling through biosynthesis pathways. To develop stable consortia, optimization of strain inoculations, nutritional divergence and crossing feeding, evolution of mutualistic growth, cell immobilization, and biosensors may potentially be used to control cell populations. Another opportunity is direct integration of non-bioprocesses (e.g., microbial electrosynthesis) to power cell metabolism and improve carbon efficiency. Additionally, metabolic modeling and 13C-metabolic flux analysis of mixed culture metabolism and cross-feeding offers a computational approach to complement experimental research for improved consortia performance.
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Affiliation(s)
- Garrett W Roell
- Department of Energy, Environmental and Chemical Engineering, Washington University, Saint Louis, MO, 63130, USA
| | - Jian Zha
- Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, 110 Eighth Street, Troy, NY, 12180, USA
| | - Rhiannon R Carr
- Department of Energy, Environmental and Chemical Engineering, Washington University, Saint Louis, MO, 63130, USA
| | - Mattheos A Koffas
- Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, 110 Eighth Street, Troy, NY, 12180, USA
| | - Stephen S Fong
- Department of Chemical and Life Science Engineering, Virginia Commonwealth University, Richmond, VA, 23284, USA
| | - Yinjie J Tang
- Department of Energy, Environmental and Chemical Engineering, Washington University, Saint Louis, MO, 63130, USA.
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Liu H, Sun J, Chang JS, Shukla P. Engineering microbes for direct fermentation of cellulose to bioethanol. Crit Rev Biotechnol 2018; 38:1089-1105. [DOI: 10.1080/07388551.2018.1452891] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
- Hao Liu
- State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou, China
| | - Jianliang Sun
- State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou, China
| | - Jo-Shu Chang
- Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan, China
| | - Pratyoosh Shukla
- Enzyme Technology and Protein Bioinformatics Laboratory, Department of Microbiology, Maharshi Dayanand University, Rohtak, India
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18
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Free A, McDonald MA, Pagaling E. Diversity-Function Relationships in Natural, Applied, and Engineered Microbial Ecosystems. ADVANCES IN APPLIED MICROBIOLOGY 2018; 105:131-189. [PMID: 30342721 DOI: 10.1016/bs.aambs.2018.07.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The connection between ecosystem function and taxonomic diversity has been of interest and relevance to macroecologists for decades. After many years of lagging behind due to the difficulty of assigning both taxonomy and function to poorly distinguishable microscopic cells, microbial ecology now has access to a suite of powerful molecular tools which allow its practitioners to generate data relating to diversity and function of a microbial community on an unprecedented scale. Instead, the problem facing today's microbial ecologists is coupling the ease of generation of these datasets with the formulation and testing of workable hypotheses relating the diversity and function of environmental, host-associated, and engineered microbial communities. Here, we review the current state of knowledge regarding the links between taxonomic alpha- and beta-diversity and ecosystem function, comparing our knowledge in this area to that obtained by macroecologists who use more traditional techniques. We consider the methodologies that can be applied to study these properties and how successful they are at linking function to diversity, using examples from the study of model microbial ecosystems, methanogenic bioreactors (anaerobic digesters), and host-associated microbiota. Finally, we assess ways in which our newly acquired understanding might be used to manipulate diversity in ecosystems of interest in order to improve function for the benefit of us or the environment in general through the provision of ecosystem services.
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Affiliation(s)
- Andrew Free
- School of Biological Sciences, The University of Edinburgh, Edinburgh, United Kingdom
| | - Michael A McDonald
- School of Biological Sciences, The University of Edinburgh, Edinburgh, United Kingdom
| | - Eulyn Pagaling
- The James Hutton Institute, Craigiebuckler, Aberdeen, United Kingdom
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19
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Strang O, Ács N, Wirth R, Maróti G, Bagi Z, Rákhely G, Kovács KL. Bioaugmentation of the thermophilic anaerobic biodegradation of cellulose and corn stover. Anaerobe 2017; 46:104-113. [DOI: 10.1016/j.anaerobe.2017.05.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 05/16/2017] [Accepted: 05/24/2017] [Indexed: 12/26/2022]
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20
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Fischer J, Lopes VS, Cardoso SL, Coutinho Filho U, Cardoso VL. MACHINE LEARNING TECHNIQUES APPLIED TO LIGNOCELLULOSIC ETHANOL IN SIMULTANEOUS HYDROLYSIS AND FERMENTATION. BRAZILIAN JOURNAL OF CHEMICAL ENGINEERING 2017. [DOI: 10.1590/0104-6632.20170341s20150475] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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21
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Singh N, Mathur AS, Tuli DK, Gupta RP, Barrow CJ, Puri M. Cellulosic ethanol production via consolidated bioprocessing by a novel thermophilic anaerobic bacterium isolated from a Himalayan hot spring. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:73. [PMID: 28344648 PMCID: PMC5361838 DOI: 10.1186/s13068-017-0756-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2016] [Accepted: 03/10/2017] [Indexed: 05/07/2023]
Abstract
BACKGROUND Cellulose-degrading thermophilic anaerobic bacterium as a suitable host for consolidated bioprocessing (CBP) has been proposed as an economically suited platform for the production of second-generation biofuels. To recognize the overall objective of CBP, fermentation using co-culture of different cellulolytic and sugar-fermenting thermophilic anaerobic bacteria has been widely studied as an approach to achieving improved ethanol production. We assessed monoculture and co-culture fermentation of novel thermophilic anaerobic bacterium for ethanol production from real substrates under controlled conditions. RESULTS In this study, Clostridium sp. DBT-IOC-C19, a cellulose-degrading thermophilic anaerobic bacterium, was isolated from the cellulolytic enrichment cultures obtained from a Himalayan hot spring. Strain DBT-IOC-C19 exhibited a broad substrate spectrum and presented single-step conversion of various cellulosic and hemicellulosic substrates to ethanol, acetate, and lactate with ethanol being the major fermentation product. Additionally, the effect of varying cellulose concentrations on the fermentation performance of the strain was studied, indicating a maximum cellulose utilization ability of 10 g L-1 cellulose. Avicel degradation kinetics of the strain DBT-IOC-C19 displayed 94.6% degradation at 5 g L-1 and 82.74% degradation at 10 g L-1 avicel concentration within 96 h of fermentation. In a comparative study with Clostridium thermocellum DSM 1313, the ethanol and total product concentrations were higher by the newly isolated strain on pretreated rice straw at an equivalent substrate loading. Three different co-culture combinations were used on various substrates that presented two-fold yield improvement than the monoculture during batch fermentation. CONCLUSIONS This study demonstrated the direct fermentation ability of the novel thermophilic anaerobic bacteria on various cellulosic and hemicellulosic substrates into ethanol without the aid of any exogenous enzymes, representing CBP-based fermentation approach. Here, the broad substrate utilization spectrum of isolated cellulolytic thermophilic anaerobic bacterium was shown to be of potential utility. We demonstrated that the co-culture strategy involving novel strains is efficient in improving ethanol production from real substrate.
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Affiliation(s)
- Nisha Singh
- Bioprocessing Laboratory, Centre for Chemistry and Biotechnology, Deakin University, Waurn Ponds, VIC 3217 Australia
- DBT-IOC Centre for Advance Bioenergy Research, Research & Development Centre, Indian Oil Corporation Limited, Sector-13, Faridabad, 121007 India
| | - Anshu S. Mathur
- DBT-IOC Centre for Advance Bioenergy Research, Research & Development Centre, Indian Oil Corporation Limited, Sector-13, Faridabad, 121007 India
| | - Deepak K. Tuli
- DBT-IOC Centre for Advance Bioenergy Research, Research & Development Centre, Indian Oil Corporation Limited, Sector-13, Faridabad, 121007 India
| | - Ravi. P. Gupta
- DBT-IOC Centre for Advance Bioenergy Research, Research & Development Centre, Indian Oil Corporation Limited, Sector-13, Faridabad, 121007 India
| | - Colin J. Barrow
- Bioprocessing Laboratory, Centre for Chemistry and Biotechnology, Deakin University, Waurn Ponds, VIC 3217 Australia
| | - Munish Puri
- Bioprocessing Laboratory, Centre for Chemistry and Biotechnology, Deakin University, Waurn Ponds, VIC 3217 Australia
- Centre for Marine Bioproducts Development, Medical Biotechnology, Flinders University, Adelaide, Australia
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22
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Transcriptomic Responses of the Interactions between Clostridium cellulovorans 743B and Rhodopseudomonas palustris CGA009 in a Cellulose-Grown Coculture for Enhanced Hydrogen Production. Appl Environ Microbiol 2016; 82:4546-4559. [PMID: 27208134 DOI: 10.1128/aem.00789-16] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 05/11/2016] [Indexed: 12/24/2022] Open
Abstract
UNLABELLED Coculturing dark- and photofermentative bacteria is a promising strategy for enhanced hydrogen (H2) production. In this study, next-generation sequencing was used to query the global transcriptomic responses of an artificial coculture of Clostridium cellulovorans 743B and Rhodopseudomonas palustris CGA009. By analyzing differentially regulated gene expression, we showed that, consistent with the physiological observations of enhanced H2 production and cellulose degradation, the nitrogen fixation genes in R. palustris and the cellulosomal genes in C. cellulovorans were upregulated in cocultures. Unexpectedly, genes related to H2 production in C. cellulovorans were downregulated, suggesting that the enhanced H2 yield was contributed mainly by R. palustris A number of genes related to biosynthesis of volatile fatty acids (VFAs) in C. cellulovorans were upregulated, and correspondingly, a gene that mediates organic compound catabolism in R. palustris was also upregulated. Interestingly, a number of genes responsible for chemotaxis in R. palustris were upregulated, which might be elicited by the VFA concentration gradient created by C. cellulovorans In addition, genes responsible for sulfur and thiamine metabolism in C. cellulovorans were downregulated in cocultures, and this could be due to a response to pH changes. A conceptual model illustrating the interactions between the two organisms was constructed based on the transcriptomic results. IMPORTANCE The findings of this study have important biotechnology applications for biohydrogen production using renewable cellulose, which is an industrially and economically important bioenergy process. Since the molecular characteristics of the interactions of a coculture when cellulose is the substrate are still unclear, this work will be of interest to microbiologists seeking to better understand and optimize hydrogen-producing coculture systems.
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Zomorrodi AR, Segrè D. Synthetic Ecology of Microbes: Mathematical Models and Applications. J Mol Biol 2015; 428:837-61. [PMID: 26522937 DOI: 10.1016/j.jmb.2015.10.019] [Citation(s) in RCA: 121] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 10/17/2015] [Accepted: 10/21/2015] [Indexed: 12/29/2022]
Abstract
As the indispensable role of natural microbial communities in many aspects of life on Earth is uncovered, the bottom-up engineering of synthetic microbial consortia with novel functions is becoming an attractive alternative to engineering single-species systems. Here, we summarize recent work on synthetic microbial communities with a particular emphasis on open challenges and opportunities in environmental sustainability and human health. We next provide a critical overview of mathematical approaches, ranging from phenomenological to mechanistic, to decipher the principles that govern the function, dynamics and evolution of microbial ecosystems. Finally, we present our outlook on key aspects of microbial ecosystems and synthetic ecology that require further developments, including the need for more efficient computational algorithms, a better integration of empirical methods and model-driven analysis, the importance of improving gene function annotation, and the value of a standardized library of well-characterized organisms to be used as building blocks of synthetic communities.
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Affiliation(s)
| | - Daniel Segrè
- Bioinformatics Program, Boston University, Boston, MA; Department of Biology, Boston University, Boston, MA; Department of Biomedical Engineering, Boston University, Boston, MA.
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24
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Facultative Anaerobe Caldibacillus debilis GB1: Characterization and Use in a Designed Aerotolerant, Cellulose-Degrading Coculture with Clostridium thermocellum. Appl Environ Microbiol 2015; 81:5567-73. [PMID: 26048931 DOI: 10.1128/aem.00735-15] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Accepted: 06/03/2015] [Indexed: 11/20/2022] Open
Abstract
Development of a designed coculture that can achieve aerotolerant ethanogenic biofuel production from cellulose can reduce the costs of maintaining anaerobic conditions during industrial consolidated bioprocessing (CBP). To this end, a strain of Caldibacillus debilis isolated from an air-tolerant cellulolytic consortium which included a Clostridium thermocellum strain was characterized and compared with the C. debilis type strain. Characterization of isolate C. debilis GB1 and comparisons with the type strain of C. debilis revealed significant physiological differences, including (i) the absence of anaerobic metabolism in the type strain and (ii) different end product synthesis profiles under the experimental conditions used. The designed cocultures displayed unique responses to oxidative conditions, including an increase in lactate production. We show here that when the two species were cultured together, the noncellulolytic facultative anaerobe C. debilis GB1 provided respiratory protection for C. thermocellum, allowing the synergistic utilization of cellulose even under an aerobic atmosphere.
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25
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Akinosho H, Yee K, Close D, Ragauskas A. The emergence of Clostridium thermocellum as a high utility candidate for consolidated bioprocessing applications. Front Chem 2014; 2:66. [PMID: 25207268 PMCID: PMC4143619 DOI: 10.3389/fchem.2014.00066] [Citation(s) in RCA: 105] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Accepted: 07/28/2014] [Indexed: 01/25/2023] Open
Abstract
First isolated in 1926, Clostridium thermocellum has recently received increased attention as a high utility candidate for use in consolidated bioprocessing (CBP) applications. These applications, which seek to process lignocellulosic biomass directly into useful products such as ethanol, are gaining traction as economically feasible routes toward the production of fuel and other high value chemical compounds as the shortcomings of fossil fuels become evident. This review evaluates C. thermocellum's role in this transitory process by highlighting recent discoveries relating to its genomic, transcriptomic, proteomic, and metabolomic responses to varying biomass sources, with a special emphasis placed on providing an overview of its unique, multivariate enzyme cellulosome complex and the role that this structure performs during biomass degradation. Both naturally evolved and genetically engineered strains are examined in light of their unique attributes and responses to various biomass treatment conditions, and the genetic tools that have been employed for their creation are presented. Several future routes for potential industrial usage are presented, and it is concluded that, although there have been many advances to significantly improve C. thermocellum's amenability to industrial use, several hurdles still remain to be overcome as this unique organism enjoys increased attention within the scientific community.
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Affiliation(s)
- Hannah Akinosho
- School of Chemistry and Biochemistry, Institute of Paper Science and Technology, Georgia Institute of Technology Atlanta, GA, USA ; Oak Ridge National Laboratory, BioEnergy Science Center Oak Ridge, TN, USA
| | - Kelsey Yee
- Oak Ridge National Laboratory, BioEnergy Science Center Oak Ridge, TN, USA ; Biosciences Division, Oak Ridge National Laboratory Oak Ridge, TN, USA
| | - Dan Close
- Biosciences Division, Oak Ridge National Laboratory Oak Ridge, TN, USA
| | - Arthur Ragauskas
- Oak Ridge National Laboratory, BioEnergy Science Center Oak Ridge, TN, USA ; Department of Chemical and Biomolecular Engineering and Department of Forestry, Wildlife, and Fisheries, University of Tennessee Knoxville, TN, USA
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26
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Schellenberg JJ, Verbeke TJ, McQueen P, Krokhin OV, Zhang X, Alvare G, Fristensky B, Thallinger GG, Henrissat B, Wilkins JA, Levin DB, Sparling R. Enhanced whole genome sequence and annotation of Clostridium stercorarium DSM8532T using RNA-seq transcriptomics and high-throughput proteomics. BMC Genomics 2014; 15:567. [PMID: 24998381 PMCID: PMC4102724 DOI: 10.1186/1471-2164-15-567] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Accepted: 06/26/2014] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND Growing interest in cellulolytic clostridia with potential for consolidated biofuels production is mitigated by low conversion of raw substrates to desired end products. Strategies to improve conversion are likely to benefit from emerging techniques to define molecular systems biology of these organisms. Clostridium stercorarium DSM8532T is an anaerobic thermophile with demonstrated high ethanol production on cellulose and hemicellulose. Although several lignocellulolytic enzymes in this organism have been well-characterized, details concerning carbohydrate transporters and central metabolism have not been described. Therefore, the goal of this study is to define an improved whole genome sequence (WGS) for this organism using in-depth molecular profiling by RNA-seq transcriptomics and tandem mass spectrometry-based proteomics. RESULTS A paired-end Roche/454 WGS assembly was closed through application of an in silico algorithm designed to resolve repetitive sequence regions, resulting in a circular replicon with one gap and a region of 2 kilobases with 10 ambiguous bases. RNA-seq transcriptomics resulted in nearly complete coverage of the genome, identifying errors in homopolymer length attributable to 454 sequencing. Peptide sequences resulting from high-throughput tandem mass spectrometry of trypsin-digested protein extracts were mapped to 1,755 annotated proteins (68% of all protein-coding regions). Proteogenomic analysis confirmed the quality of annotation and improvement pipelines, identifying a missing gene and an alternative reading frame. Peptide coverage of genes hypothetically involved in substrate hydrolysis, transport and utilization confirmed multiple pathways for glycolysis, pyruvate conversion and recycling of intermediates. No sequences homologous to transaldolase, a central enzyme in the pentose phosphate pathway, were observed by any method, despite demonstrated growth of this organism on xylose and xylan hemicellulose. CONCLUSIONS Complementary omics techniques confirm the quality of genome sequence assembly, annotation and error-reporting. Nearly complete genome coverage by RNA-seq likely indicates background DNA in RNA extracts, however these preps resulted in WGS enhancement and transcriptome profiling in a single Illumina run. No detection of transaldolase by any method despite xylose utilization by this organism indicates an alternative pathway for sedoheptulose-7-phosphate degradation. This report combines next-generation omics techniques to elucidate previously undefined features of substrate transport and central metabolism for this organism and its potential for consolidated biofuels production from lignocellulose.
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Affiliation(s)
| | - Tobin J Verbeke
- />Department of Microbiology, University of Manitoba, Winnipeg, Canada
| | - Peter McQueen
- />Manitoba Centre for Proteomics and Systems Biology, University of Manitoba, Winnipeg, Canada
| | - Oleg V Krokhin
- />Manitoba Centre for Proteomics and Systems Biology, University of Manitoba, Winnipeg, Canada
| | - Xiangli Zhang
- />Department of Plant Sciences, University of Manitoba, Winnipeg, Canada
| | - Graham Alvare
- />Department of Plant Sciences, University of Manitoba, Winnipeg, Canada
| | - Brian Fristensky
- />Department of Plant Sciences, University of Manitoba, Winnipeg, Canada
| | - Gerhard G Thallinger
- />Core Facility Bioinformatics, Austrian Centre of Industrial Biotechnology (ACIB), Graz, Austria
- />Institute for Genomics and Bioinformatics, Graz University of Technology, Graz, Austria
| | - Bernard Henrissat
- />Architecture et Fonction des Macromolécules Biologiques, Université Aix-Marseille, Marseille, France
- />UMR 7257, Centre National de Recherche Scientifique, 163 ave. de Luminy, Marseille, 13288 France
| | - John A Wilkins
- />Manitoba Centre for Proteomics and Systems Biology, University of Manitoba, Winnipeg, Canada
| | - David B Levin
- />Department of Biosystems Engineering, University of Manitoba, Winnipeg, Canada
| | - Richard Sparling
- />Department of Microbiology, University of Manitoba, Winnipeg, Canada
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Blumer-Schuette SE, Brown SD, Sander KB, Bayer EA, Kataeva I, Zurawski JV, Conway JM, Adams MWW, Kelly RM. Thermophilic lignocellulose deconstruction. FEMS Microbiol Rev 2014; 38:393-448. [DOI: 10.1111/1574-6976.12044] [Citation(s) in RCA: 128] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Revised: 08/20/2013] [Accepted: 08/28/2013] [Indexed: 11/28/2022] Open
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Clarkson SM, Hamilton-Brehm SD, Giannone RJ, Engle NL, Tschaplinski TJ, Hettich RL, Elkins JG. A comparative multidimensional LC-MS proteomic analysis reveals mechanisms for furan aldehyde detoxification in Thermoanaerobacter pseudethanolicus 39E. BIOTECHNOLOGY FOR BIOFUELS 2014; 7:165. [PMID: 25506391 PMCID: PMC4265447 DOI: 10.1186/s13068-014-0165-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 11/07/2014] [Indexed: 05/07/2023]
Abstract
BACKGROUND Chemical and physical pretreatment of lignocellulosic biomass improves substrate reactivity for increased microbial biofuel production, but also restricts growth via the release of furan aldehydes, such as furfural and 5-hydroxymethylfurfural (5-HMF). The physiological effects of these inhibitors on thermophilic, fermentative bacteria are important to understand; especially as cellulolytic strains are being developed for consolidated bioprocessing (CBP) of lignocellulosic feedstocks. Identifying mechanisms for detoxification of aldehydes in naturally resistant strains, such as Thermoanaerobacter spp., may also enable improvements in candidate CBP microorganisms. RESULTS Thermoanaerobacter pseudethanolicus 39E, an anaerobic, saccharolytic thermophile, was found to grow readily in the presence of 30 mM furfural and 20 mM 5-HMF and reduce these aldehydes to their respective alcohols in situ. The proteomes of T. pseudethanolicus 39E grown in the presence or absence of 15 mM furfural were compared to identify upregulated enzymes potentially responsible for the observed reduction. A total of 225 proteins were differentially regulated in response to the 15 mM furfural treatment with 152 upregulated versus 73 downregulated. Only 87 proteins exhibited a twofold or greater change in abundance in either direction. Of these, 54 were upregulated in the presence of furfural and 33 were downregulated. Two oxidoreductases were upregulated at least twofold by furfural and were targeted for further investigation. Teth39_1597 encodes a predicted butanol dehydrogenase (BdhA) and Teth39_1598, a predicted aldo/keto reductase (AKR). Both genes were cloned from T. pseudethanolicus 39E, with the respective enzymes overexpressed in E. coli and specific activities determined against a variety of aldehydes. Overexpressed BdhA showed significant activity with all aldehydes tested, including furfural and 5-HMF, using NADPH as the cofactor. Cell extracts with AKR also showed activity with NADPH, but only with four-carbon butyraldehyde and isobutyraldehyde. CONCLUSIONS T. pseudethanolicus 39E displays intrinsic tolerance to the common pretreatment inhibitors furfural and 5-HMF. Multidimensional proteomic analysis was used as an effective tool to identify putative mechanisms for detoxification of furfural and 5-HMF. T. pseudethanolicus was found to upregulate an NADPH-dependent alcohol dehydrogenase 6.8-fold in response to furfural. In vitro enzyme assays confirmed the reduction of furfural and 5-HMF to their respective alcohols.
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Affiliation(s)
- Sonya M Clarkson
- />BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6341 USA
- />Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6341 USA
| | - Scott D Hamilton-Brehm
- />BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6341 USA
- />Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6341 USA
- />Current address: Division of Earth and Ecosystem Sciences, Desert Research Institute, Las Vegas, NV USA
| | - Richard J Giannone
- />BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6341 USA
- />Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6341 USA
| | - Nancy L Engle
- />BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6341 USA
- />Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6341 USA
| | - Timothy J Tschaplinski
- />BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6341 USA
- />Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6341 USA
| | - Robert L Hettich
- />BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6341 USA
- />Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6341 USA
| | - James G Elkins
- />BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6341 USA
- />Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6341 USA
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Holwerda EK, Thorne PG, Olson DG, Amador-Noguez D, Engle NL, Tschaplinski TJ, van Dijken JP, Lynd LR. The exometabolome of Clostridium thermocellum reveals overflow metabolism at high cellulose loading. BIOTECHNOLOGY FOR BIOFUELS 2014; 7:155. [PMID: 25379055 PMCID: PMC4207885 DOI: 10.1186/s13068-014-0155-1] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2014] [Accepted: 10/03/2014] [Indexed: 05/18/2023]
Abstract
BACKGROUND Clostridium thermocellum is a model thermophilic organism for the production of biofuels from lignocellulosic substrates. The majority of publications studying the physiology of this organism use substrate concentrations of ≤10 g/L. However, industrially relevant concentrations of substrate start at 100 g/L carbohydrate, which corresponds to approximately 150 g/L solids. To gain insight into the physiology of fermentation of high substrate concentrations, we studied the growth on, and utilization of high concentrations of crystalline cellulose varying from 50 to 100 g/L by C. thermocellum. RESULTS Using a defined medium, batch cultures of C. thermocellum achieved 93% conversion of cellulose (Avicel) initially present at 100 g/L. The maximum rate of substrate utilization increased with increasing substrate loading. During fermentation of 100 g/L cellulose, growth ceased when about half of the substrate had been solubilized. However, fermentation continued in an uncoupled mode until substrate utilization was almost complete. In addition to commonly reported fermentation products, amino acids - predominantly L-valine and L-alanine - were secreted at concentrations up to 7.5 g/L. Uncoupled metabolism was also accompanied by products not documented previously for C. thermocellum, including isobutanol, meso- and RR/SS-2,3-butanediol and trace amounts of 3-methyl-1-butanol, 2-methyl-1-butanol and 1-propanol. We hypothesize that C. thermocellum uses overflow metabolism to balance its metabolism around the pyruvate node in glycolysis. CONCLUSIONS C. thermocellum is able to utilize industrially relevant concentrations of cellulose, up to 93 g/L. We report here one of the highest degrees of crystalline cellulose utilization observed thus far for a pure culture of C. thermocellum, the highest maximum substrate utilization rate and the highest amount of isobutanol produced by a wild-type organism.
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Affiliation(s)
- Evert K Holwerda
- />Thayer School of Engineering, Dartmouth College, Hanover, NH 03755 USA
- />BioEnergy Science Center, Oak Ridge, TN 37830 USA
| | | | - Daniel G Olson
- />Thayer School of Engineering, Dartmouth College, Hanover, NH 03755 USA
- />BioEnergy Science Center, Oak Ridge, TN 37830 USA
| | - Daniel Amador-Noguez
- />Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706 USA
| | - Nancy L Engle
- />BioEnergy Science Center, Oak Ridge, TN 37830 USA
- />Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830 USA
| | - Timothy J Tschaplinski
- />BioEnergy Science Center, Oak Ridge, TN 37830 USA
- />Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830 USA
| | - Johannes P van Dijken
- />Emeritus Industrial Biotechnology of Delft University of Technology, Delft, BC 2628 The Netherlands
| | - Lee R Lynd
- />Thayer School of Engineering, Dartmouth College, Hanover, NH 03755 USA
- />BioEnergy Science Center, Oak Ridge, TN 37830 USA
- />Mascoma Corporation, Lebanon, NH 03766 USA
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Thermoanaerobacter thermohydrosulfuricus WC1 shows protein complement stability during fermentation of key lignocellulose-derived substrates. Appl Environ Microbiol 2013; 80:1602-15. [PMID: 24362431 DOI: 10.1128/aem.03555-13] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Thermoanaerobacter spp. have long been considered suitable Clostridium thermocellum coculture partners for improving lignocellulosic biofuel production through consolidated bioprocessing. However, studies using "omic"-based profiling to better understand carbon utilization and biofuel producing pathways have been limited to only a few strains thus far. To better characterize carbon and electron flux pathways in the recently isolated, xylanolytic strain, Thermoanaerobacter thermohydrosulfuricus WC1, label-free quantitative proteomic analyses were combined with metabolic profiling. SWATH-MS proteomic analysis quantified 832 proteins in each of six proteomes isolated from mid-exponential-phase cells grown on xylose, cellobiose, or a mixture of both. Despite encoding genes consistent with a carbon catabolite repression network observed in other Gram-positive organisms, simultaneous consumption of both substrates was observed. Lactate was the major end product of fermentation under all conditions despite the high expression of gene products involved with ethanol and/or acetate synthesis, suggesting that carbon flux in this strain may be controlled via metabolite-based (allosteric) regulation or is constrained by metabolic bottlenecks. Cross-species "omic" comparative analyses confirmed similar expression patterns for end-product-forming gene products across diverse Thermoanaerobacter spp. It also identified differences in cofactor metabolism, which potentially contribute to differences in end-product distribution patterns between the strains analyzed. The analyses presented here improve our understanding of T. thermohydrosulfuricus WC1 metabolism and identify important physiological limitations to be addressed in its development as a biotechnologically relevant strain in ethanologenic designer cocultures through consolidated bioprocessing.
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Metabolic adaption of ethanol-tolerant Clostridium thermocellum. PLoS One 2013; 8:e70631. [PMID: 23936233 PMCID: PMC3728321 DOI: 10.1371/journal.pone.0070631] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Accepted: 06/19/2013] [Indexed: 11/20/2022] Open
Abstract
Clostridium thermocellum is a major candidate for bioethanol production via consolidated bioprocessing. However, the low ethanol tolerance of the organism dramatically impedes its usage in industry. To explore the mechanism of ethanol tolerance in this microorganism, systematic metabolomics was adopted to analyse the metabolic phenotypes of a C. thermocellum wild-type (WT) strain and an ethanol-tolerant strain cultivated without (ET0) or with (ET3) 3% (v/v) exogenous ethanol. Metabolomics analysis elucidated that the levels of numerous metabolites in different pathways were changed for the metabolic adaption of ethanol-tolerant C. thermocellum. The most interesting phenomenon was that cellodextrin was significantly more accumulated in the ethanol-tolerant strain compared with the WT strain, although cellobiose was completely consumed in both the ethanol-tolerant and wild-type strains. These results suggest that the cellodextrin synthesis was active, which might be a potential mechanism for stress resistance. Moreover, the overflow of many intermediate metabolites, which indicates the metabolic imbalance, in the ET0 cultivation was more significant than in the WT and ET3 cultivations. This indicates that the metabolic balance of the ethanol-tolerant strain was adapted better to the condition of ethanol stress. This study provides additional insight into the mechanism of ethanol tolerance and is valuable for further metabolic engineering aimed at higher bioethanol production.
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Verbeke TJ, Zhang X, Henrissat B, Spicer V, Rydzak T, Krokhin OV, Fristensky B, Levin DB, Sparling R. Genomic evaluation of Thermoanaerobacter spp. for the construction of designer co-cultures to improve lignocellulosic biofuel production. PLoS One 2013; 8:e59362. [PMID: 23555660 PMCID: PMC3608648 DOI: 10.1371/journal.pone.0059362] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Accepted: 02/13/2013] [Indexed: 02/07/2023] Open
Abstract
The microbial production of ethanol from lignocellulosic biomass is a multi-component process that involves biomass hydrolysis, carbohydrate transport and utilization, and finally, the production of ethanol. Strains of the genus Thermoanaerobacter have been studied for decades due to their innate abilities to produce comparatively high ethanol yields from hemicellulose constituent sugars. However, their inability to hydrolyze cellulose, limits their usefulness in lignocellulosic biofuel production. As such, co-culturing Thermoanaerobacter spp. with cellulolytic organisms is a plausible approach to improving lignocellulose conversion efficiencies and yields of biofuels. To evaluate native lignocellulosic ethanol production capacities relative to competing fermentative end-products, comparative genomic analysis of 11 sequenced Thermoanaerobacter strains, including a de novo genome, Thermoanaerobacter thermohydrosulfuricus WC1, was conducted. Analysis was specifically focused on the genomic potential for each strain to address all aspects of ethanol production mentioned through a consolidated bioprocessing approach. Whole genome functional annotation analysis identified three distinct clades within the genus. The genomes of Clade 1 strains encode the fewest extracellular carbohydrate active enzymes and also show the least diversity in terms of lignocellulose relevant carbohydrate utilization pathways. However, these same strains reportedly are capable of directing a higher proportion of their total carbon flux towards ethanol, rather than non-biofuel end-products, than other Thermoanaerobacter strains. Strains in Clade 2 show the greatest diversity in terms of lignocellulose hydrolysis and utilization, but proportionately produce more non-ethanol end-products than Clade 1 strains. Strains in Clade 3, in which T. thermohydrosulfuricus WC1 is included, show mid-range potential for lignocellulose hydrolysis and utilization, but also exhibit extensive divergence from both Clade 1 and Clade 2 strains in terms of cellular energetics. The potential implications regarding strain selection and suitability for industrial ethanol production through a consolidated bioprocessing co-culturing approach are examined throughout the manuscript.
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Affiliation(s)
- Tobin J. Verbeke
- Department of Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Xiangli Zhang
- Department of Plant Science, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Bernard Henrissat
- Centre national de la recherche scientifique, Aix-Marseille Université, Marseille, France
| | - Vic Spicer
- Department of Physics & Astronomy, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Thomas Rydzak
- Department of Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Oleg V. Krokhin
- Department of Internal Medicine & Manitoba Centre for Proteomics and Systems Biology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Brian Fristensky
- Department of Plant Science, University of Manitoba, Winnipeg, Manitoba, Canada
| | - David B. Levin
- Biosystems Engineering, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Richard Sparling
- Department of Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada
- * E-mail:
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Song N, Cai HY, Yan ZS, Jiang HL. Cellulose degradation by one mesophilic strain Caulobacter sp. FMC1 under both aerobic and anaerobic conditions. BIORESOURCE TECHNOLOGY 2013; 131:281-7. [PMID: 23357088 DOI: 10.1016/j.biortech.2013.01.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Revised: 12/31/2012] [Accepted: 01/02/2013] [Indexed: 05/10/2023]
Abstract
Caulobacteria are presumed to be responsible for considerable mineralization of organic material in aquatic environments. In this study, a facultative, mesophilic and cellulolytic bacterium Caulobacter sp. FMC1 was isolated from sediments which were taken from a shallow freshwater lake and then enriched with amendment of submerged macrophyte for three months. This strain seemed to evolve a capacity to adapt redox-fluctuating environments, and could degrade cellulose both aerobically and anaerobically. Cellulose degradation percentages under aerobic and anaerobic conditions were approximately 27% and 10% after a 240-h incubation in liquid mediums containing 0.5% cellulose, respectively. Either cellulose or cellobiose alone was able to induce activities of endoglucanase, exoglucanase, and β-1,4-glucosidase. Interestingly, ethanol was produced as the main fermentative product under anaerobic incubation on cellulose. These results could improve our understanding about cellulose-degrading process in aquatic environments, and were also useful in optimizing cellulose bioconversion process for bioethanol production.
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Affiliation(s)
- Na Song
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, China
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Svetlitchnyi VA, Kensch O, Falkenhan DA, Korseska SG, Lippert N, Prinz M, Sassi J, Schickor A, Curvers S. Single-step ethanol production from lignocellulose using novel extremely thermophilic bacteria. BIOTECHNOLOGY FOR BIOFUELS 2013; 6:31. [PMID: 23448304 PMCID: PMC3598825 DOI: 10.1186/1754-6834-6-31] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2012] [Accepted: 02/04/2013] [Indexed: 05/07/2023]
Abstract
BACKGROUND Consolidated bioprocessing (CBP) of lignocellulosic biomass to ethanol using thermophilic bacteria provides a promising solution for efficient lignocellulose conversion without the need for additional cellulolytic enzymes. Most studies on the thermophilic CBP concentrate on co-cultivation of the thermophilic cellulolytic bacterium Clostridium thermocellum with non-cellulolytic thermophilic anaerobes at temperatures of 55°C-60°C. RESULTS We have specifically screened for cellulolytic bacteria growing at temperatures >70°C to enable direct conversion of lignocellulosic materials into ethanol. Seven new strains of extremely thermophilic anaerobic cellulolytic bacteria of the genus Caldicellulosiruptor and eight new strains of extremely thermophilic xylanolytic/saccharolytic bacteria of the genus Thermoanaerobacter isolated from environmental samples exhibited fast growth at 72°C, extensive lignocellulose degradation and high yield ethanol production on cellulose and pretreated lignocellulosic biomass. Monocultures of Caldicellulosiruptor strains degraded up to 89-97% of the cellulose and hemicellulose polymers in pretreated biomass and produced up to 72 mM ethanol on cellulose without addition of exogenous enzymes. In dual co-cultures of Caldicellulosiruptor strains with Thermoanaerobacter strains the ethanol concentrations rose 2- to 8.2-fold compared to cellulolytic monocultures. A co-culture of Caldicellulosiruptor DIB 087C and Thermoanaerobacter DIB 097X was particularly effective in the conversion of cellulose to ethanol, ethanol comprising 34.8 mol% of the total organic products. In contrast, a co-culture of Caldicellulosiruptor saccharolyticus DSM 8903 and Thermoanaerobacter mathranii subsp. mathranii DSM 11426 produced only low amounts of ethanol. CONCLUSIONS The newly discovered Caldicellulosiruptor sp. strain DIB 004C was capable of producing unexpectedly large amounts of ethanol from lignocellulose in fermentors. The established co-cultures of new Caldicellulosiruptor strains with new Thermoanaerobacter strains underline the importance of using specific strain combinations for high ethanol yields. These co-cultures provide an efficient CBP pathway for ethanol production and represent an ideal starting point for development of a highly integrated commercial ethanol production process.
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Affiliation(s)
| | - Oliver Kensch
- Direvo Industrial Biotechnology GmbH, Nattermannallee 1, D-50259, Köln, Germany
| | - Doris A Falkenhan
- Direvo Industrial Biotechnology GmbH, Nattermannallee 1, D-50259, Köln, Germany
| | - Svenja G Korseska
- Direvo Industrial Biotechnology GmbH, Nattermannallee 1, D-50259, Köln, Germany
| | - Nadine Lippert
- Direvo Industrial Biotechnology GmbH, Nattermannallee 1, D-50259, Köln, Germany
| | - Melanie Prinz
- Direvo Industrial Biotechnology GmbH, Nattermannallee 1, D-50259, Köln, Germany
| | - Jamaleddine Sassi
- Direvo Industrial Biotechnology GmbH, Nattermannallee 1, D-50259, Köln, Germany
| | - Anke Schickor
- Direvo Industrial Biotechnology GmbH, Nattermannallee 1, D-50259, Köln, Germany
| | - Simon Curvers
- Direvo Industrial Biotechnology GmbH, Nattermannallee 1, D-50259, Köln, Germany
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Comparative metagenomic analysis of microcosm structures and lignocellulolytic enzyme systems of symbiotic biomass-degrading consortia. Appl Microbiol Biotechnol 2013; 97:8941-54. [DOI: 10.1007/s00253-013-4699-y] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Revised: 01/03/2013] [Accepted: 01/07/2013] [Indexed: 10/27/2022]
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Xia Y, Fang HHP, Zhang T. Recent studies on thermophilic anaerobic bioconversion of lignocellulosic biomass. RSC Adv 2013. [DOI: 10.1039/c3ra40866c] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Continuous cellulosic bioethanol fermentation by cyclic fed-batch cocultivation. Appl Environ Microbiol 2012; 79:1580-9. [PMID: 23275517 DOI: 10.1128/aem.02617-12] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cocultivation of cellulolytic and saccharolytic microbial populations is a promising strategy to improve bioethanol production from the fermentation of recalcitrant cellulosic materials. Earlier studies have demonstrated the effectiveness of cocultivation in enhancing ethanolic fermentation of cellulose in batch fermentation. To further enhance process efficiency, a semicontinuous cyclic fed-batch fermentor configuration was evaluated for its potential in enhancing the efficiency of cellulose fermentation using cocultivation. Cocultures of cellulolytic Clostridium thermocellum LQRI and saccharolytic Thermoanaerobacter pseudethanolicus strain X514 were tested in the semicontinuous fermentor as a model system. Initial cellulose concentration and pH were identified as the key process parameters controlling cellulose fermentation performance in the fixed-volume cyclic fed-batch coculture system. At an initial cellulose concentration of 40 g liter(-1), the concentration of ethanol produced with pH control was 4.5-fold higher than that without pH control. It was also found that efficient cellulosic bioethanol production by cocultivation was sustained in the semicontinuous configuration, with bioethanol production reaching 474 mM in 96 h with an initial cellulose concentration of 80 g liter(-1) and pH controlled at 6.5 to 6.8. These results suggested the advantages of the cyclic fed-batch process for cellulosic bioethanol fermentation by the cocultures.
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Quantitative proteomic analysis of secretome of microbial consortium during saw dust utilization. J Proteomics 2012; 75:5590-603. [DOI: 10.1016/j.jprot.2012.08.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2012] [Revised: 07/28/2012] [Accepted: 08/13/2012] [Indexed: 11/23/2022]
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Zhang X, Ye X, Finneran KT, Zilles JL, Morgenroth E. Interactions betweenClostridium beijerinckiiandGeobacter metallireducensin co-culture fermentation with anthrahydroquinone-2, 6-disulfonate (AH2QDS) for enhanced biohydrogen production from xylose. Biotechnol Bioeng 2012; 110:164-72. [DOI: 10.1002/bit.24627] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Revised: 07/19/2012] [Accepted: 07/26/2012] [Indexed: 11/10/2022]
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Feng X, Xu Y, Chen Y, Tang YJ. MicrobesFlux: a web platform for drafting metabolic models from the KEGG database. BMC SYSTEMS BIOLOGY 2012; 6:94. [PMID: 22857267 PMCID: PMC3447728 DOI: 10.1186/1752-0509-6-94] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/06/2012] [Accepted: 07/17/2012] [Indexed: 01/03/2023]
Abstract
Background Concurrent with the efforts currently underway in mapping microbial genomes using high-throughput sequencing methods, systems biologists are building metabolic models to characterize and predict cell metabolisms. One of the key steps in building a metabolic model is using multiple databases to collect and assemble essential information about genome-annotations and the architecture of the metabolic network for a specific organism. To speed up metabolic model development for a large number of microorganisms, we need a user-friendly platform to construct metabolic networks and to perform constraint-based flux balance analysis based on genome databases and experimental results. Results We have developed a semi-automatic, web-based platform (MicrobesFlux) for generating and reconstructing metabolic models for annotated microorganisms. MicrobesFlux is able to automatically download the metabolic network (including enzymatic reactions and metabolites) of ~1,200 species from the KEGG database (Kyoto Encyclopedia of Genes and Genomes) and then convert it to a metabolic model draft. The platform also provides diverse customized tools, such as gene knockouts and the introduction of heterologous pathways, for users to reconstruct the model network. The reconstructed metabolic network can be formulated to a constraint-based flux model to predict and analyze the carbon fluxes in microbial metabolisms. The simulation results can be exported in the SBML format (The Systems Biology Markup Language). Furthermore, we also demonstrated the platform functionalities by developing an FBA model (including 229 reactions) for a recent annotated bioethanol producer, Thermoanaerobacter sp. strain X514, to predict its biomass growth and ethanol production. Conclusion MicrobesFlux is an installation-free and open-source platform that enables biologists without prior programming knowledge to develop metabolic models for annotated microorganisms in the KEGG database. Our system facilitates users to reconstruct metabolic networks of organisms based on experimental information. Through human-computer interaction, MicrobesFlux provides users with reasonable predictions of microbial metabolism via flux balance analysis. This prototype platform can be a springboard for advanced and broad-scope modeling of complex biological systems by integrating other “omics” data or 13 C- metabolic flux analysis results. MicrobesFlux is available at http://tanglab.engineering.wustl.edu/static/MicrobesFlux.html and will be continuously improved based on feedback from users.
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Affiliation(s)
- Xueyang Feng
- Department of Energy, Environmental and Chemical Engineering, Washington University, Saint Louis, MO 63130, USA.
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