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Poehlein A, Zeldes B, Flaiz M, Böer T, Lüschen A, Höfele F, Baur KS, Molitor B, Kröly C, Wang M, Zhang Q, Fan Y, Chao W, Daniel R, Li F, Basen M, Müller V, Angenent LT, Sousa DZ, Bengelsdorf FR. Advanced aspects of acetogens. BIORESOURCE TECHNOLOGY 2025; 427:131913. [PMID: 39626805 DOI: 10.1016/j.biortech.2024.131913] [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: 06/26/2024] [Revised: 11/28/2024] [Accepted: 11/28/2024] [Indexed: 03/21/2025]
Abstract
Acetogens are a diverse group of anaerobic bacteria that are capable of carbon dioxide reduction and have for long fascinated scientists due to their unique metabolic prowess. Historically, acetogens have been recognized for their remarkable ability to grow and to produce acetate from different one-carbon sources, including carbon dioxide, carbon monoxide, formate, methanol, and methylated organic compounds. The key metabolic pathway in acetogens responsible for converting these one-carbon sources is the Wood-Ljungdahl pathway. This review offers a comprehensive overview of the latest discoveries that are related to acetogens. It delves into a variety of topics, including newly isolated acetogens, their taxonomy and physiology and highlights novel metabolic properties. Additionally, it explores metabolic engineering strategies that are designed to expand the product range of acetogens or to understand specific traits of their metabolism. Lastly, the review presents innovative gas fermentation techniques within the context of industrial applications.
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Affiliation(s)
- Anja Poehlein
- Genomic and Applied Microbiology & Göttingen Genomics Laboratory, Georg-August University, Göttingen, Germany
| | - Benjamin Zeldes
- Microbiology, Institute of Biological Sciences, University of Rostock, Rostock, Germany
| | - Maximilian Flaiz
- Laboratory of Microbiology, Wageningen University and Research, Wageningen 6708 WE, the Netherlands
| | - Tim Böer
- Genomic and Applied Microbiology & Göttingen Genomics Laboratory, Georg-August University, Göttingen, Germany
| | - Alina Lüschen
- Genomic and Applied Microbiology & Göttingen Genomics Laboratory, Georg-August University, Göttingen, Germany
| | - Franziska Höfele
- Institute of Molecular Biology and Biotechnology of Prokaryotes, University of Ulm, Ulm, Germany
| | - Kira S Baur
- Institute of Molecular Biology and Biotechnology of Prokaryotes, University of Ulm, Ulm, Germany
| | - Bastian Molitor
- Environmental Biotechnology Group, Department of Geosciences, University of Tübingen, Schnarrenbergstraße 94-96, Tübingen 72076, Germany; Cluster of Excellence - Controlling Microbes to Fight Infections, University of Tübingen, Auf der Morgenstelle 28, Tübingen 72074, Germany
| | - Christian Kröly
- Laboratory of Microbiology, Wageningen University and Research, Wageningen 6708 WE, the Netherlands; Institute of Molecular Biology and Biotechnology of Prokaryotes, University of Ulm, Ulm, Germany
| | - Meng Wang
- SINOPEC Dalian Research Institute of Petroleum and Petrochemical Co. Ltd, China
| | - Quan Zhang
- SINOPEC Dalian Research Institute of Petroleum and Petrochemical Co. Ltd, China.
| | - Yixuan Fan
- Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, China
| | - Wei Chao
- Beijing Shougang LanzaTech Technology Co. Ltd, Tianshunzhuang North Road, Shijingshan District, Beijing, China
| | - Rolf Daniel
- Genomic and Applied Microbiology & Göttingen Genomics Laboratory, Georg-August University, Göttingen, Germany
| | - Fuli Li
- Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, China
| | - Mirko Basen
- Microbiology, Institute of Biological Sciences, University of Rostock, Rostock, Germany
| | - Volker Müller
- Department of Molecular Microbiology & Bioenergetics, Institute of Molecular Biosciences, Goethe-University Frankfurt am Main, Frankfurt am Main, Germany
| | - Largus T Angenent
- Environmental Biotechnology Group, Department of Geosciences, University of Tübingen, Schnarrenbergstraße 94-96, Tübingen 72076, Germany
| | - Diana Z Sousa
- Laboratory of Microbiology, Wageningen University and Research, Wageningen 6708 WE, the Netherlands
| | - Frank R Bengelsdorf
- Institute of Molecular Biology and Biotechnology of Prokaryotes, University of Ulm, Ulm, Germany.
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Choi Y, Zhou M, Ban Y, Oba M, Duval S, Guan LL. Differential alteration of rumen microbial composition in response to 3-nitrooxypropanol supplementation in dairy cattle fed high-grain and high-forage diets. J Dairy Sci 2025:S0022-0302(25)00362-5. [PMID: 40383387 DOI: 10.3168/jds.2024-26206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2024] [Accepted: 04/26/2025] [Indexed: 05/20/2025]
Abstract
Although 3-nitrooxypropanol (3-NOP) is known to effectively reduce methane (CH4) emissions in ruminants, its effect on rumen microbial communities under different dietary composition remains less understood. This study investigated how different diet compositions with 3-NOP supplementation affected rumen microbial communities in dairy cows. Rumen samples were obtained from 2 previous studies: a crossover design study with two 3-NOP levels (0 and 130 mg/kg DM) under a high-grain diet (HG; grain:forage = 60:40, n = 12), and a 3 × 3 Latin square design study with three 3-NOP levels (0, 68, and 132 mg/kg DM) under a high-forage diet (HF; grain:forage = 40:60, n = 15). A total of 138 rumen samples (HG: 48 and HF: 90 samples) were subjected to metataxonomic analysis to identify the compositional shifts of rumen microbiota (bacteria, archaea, and protozoa) in response to 3-NOP supplementation. The ruminal bacterial response to 3-NOP was more pronounced under HG diet (11 genera affected) than under HF diet (2 genera affected), with Lachnospiraceae NK3A20 group consistently increased under both diets. This bacterial group showed diet-specific fermentation patterns, correlating with increased molar proportion of butyrate under HF diet and potentially contributing to increased molar proportion of propionate under HG diet through succinate production. Methanogen responses to 3-NOP supplementation were also diet-dependent. Methanosphaera sp. increased under both diets, however, distinctive changes including contrasting responses between Methanobrevibacter (Mbb.) gottschalkii and Methanobrevibacterruminantium under HF diet were seen, reflecting their different metabolic capabilities in substrate utilization for methanogenesis in response to 3-NOP. Notably, ruminal Mbb. gottschalkii (H2-dependent) decreased, whereas Mbb. ruminantium (H2/formate-dependent) increased under HF diet, suggesting potential adaptation mechanisms to 3-NOP-induced changes in substrate availability. Ruminal protozoal communities remained unaffected under both diets. Further analysis of combined 2 studies with a batch effect correction approach revealed increases in Lachnospiraceae NK3A20 group, Saccharofermentans, Mbb. ruminantium, and Methanosphaera sp. group 5 and ISO3-F5, and decreases in Mbb. gottschalkii and Methanomassiliicoccaceae group 4 sp. MpT1 under 3-NOP supplementation. These findings demonstrate that 3-NOP has consistent effects on specific microbial taxa regardless of diet composition, and it also has diet-dependent effects on other members of the rumen microbiota. This knowledge provides valuable insights for optimizing CH4 mitigation strategies in dairy production systems under different dietary compositions.
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Affiliation(s)
- Y Choi
- Faculty of Land and Food Systems, The University of British Columbia, Vancouver, BC, Canada V6T 1Z4; Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada T6G 2P5
| | - M Zhou
- Faculty of Land and Food Systems, The University of British Columbia, Vancouver, BC, Canada V6T 1Z4; Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada T6G 2P5
| | - Y Ban
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada T6G 2P5
| | - M Oba
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada T6G 2P5; The Research Center for Animal Science, Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima 739-8528, Japan
| | - S Duval
- DSM Nutritional Products, Animal Nutrition and Health, Wurmisweg 576, 4303 Kaiseraugst, Switzerland
| | - L L Guan
- Faculty of Land and Food Systems, The University of British Columbia, Vancouver, BC, Canada V6T 1Z4; Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada T6G 2P5.
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Liu F, Wang T, Feng L, Chen Y. The mechanisms of pH regulation on promoting volatile fatty acids production from kitchen waste. J Environ Sci (China) 2025; 147:414-423. [PMID: 39003059 DOI: 10.1016/j.jes.2023.10.035] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 10/29/2023] [Accepted: 10/30/2023] [Indexed: 07/15/2024]
Abstract
The anaerobic acid production experiments were conducted with the pretreated kitchen waste under pH adjustment. The results showed that pH 8 was considered to be the most suitable condition for acid production, especially for the formation of acetic acid and propionic acid. The average value of total volatile fatty acid at pH 8 was 8814 mg COD/L, 1.5 times of that under blank condition. The average yield of acetic acid and propionic acid was 3302 mg COD/L and 2891 mg COD/L, respectively. The activities of key functional enzymes such as phosphotransacetylase, acetokinase, oxaloacetate transcarboxylase and succinyl-coA transferase were all enhanced. To further explore the regulatory mechanisms within the system, the distribution of microorganisms at different levels in the fermentation system was obtained by microbial sequencing, results indicating that the relative abundances of Clostridiales, Bacteroidales, Chloroflexi, Clostridium, Bacteroidetes and Propionibacteriales, which were great contributors for the hydrolysis and acidification, increased rapidly at pH 8 compared with the blank group. Besides, the proportion of genes encoding key enzymes was generally increased, which further verified the mechanism of hydrolytic acidification and acetic acid production of organic matter under pH regulation.
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Affiliation(s)
- Feng Liu
- College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; TUS-Environmental Science and Technology Development Co., Ltd., Beijing 100084, China
| | - Tingting Wang
- College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Leiyu Feng
- College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
| | - Yinguang Chen
- College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
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Flaiz M, Poehlein A, Wilhelm W, Mook A, Daniel R, Dürre P, Bengelsdorf FR. Refining and illuminating acetogenic Eubacterium strains for reclassification and metabolic engineering. Microb Cell Fact 2024; 23:24. [PMID: 38233843 PMCID: PMC10795377 DOI: 10.1186/s12934-024-02301-8] [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: 10/27/2023] [Accepted: 01/09/2024] [Indexed: 01/19/2024] Open
Abstract
BACKGROUND The genus Eubacterium is quite diverse and includes several acetogenic strains capable of fermenting C1-substrates into valuable products. Especially, Eubacterium limosum and closely related strains attract attention not only for their capability to ferment C1 gases and liquids, but also due to their ability to produce butyrate. Apart from its well-elucidated metabolism, E. limosum is also genetically accessible, which makes it an interesting candidate to be an industrial biocatalyst. RESULTS In this study, we examined genomic, phylogenetic, and physiologic features of E. limosum and the closest related species E. callanderi as well as E. maltosivorans. We sequenced the genomes of the six Eubacterium strains 'FD' (DSM 3662T), 'Marburg' (DSM 3468), '2A' (DSM 2593), '11A' (DSM 2594), 'G14' (DSM 107592), and '32' (DSM 20517) and subsequently compared these with previously available genomes of the E. limosum type strain (DSM 20543T) as well as the strains 'B2', 'KIST612', 'YI' (DSM 105863T), and 'SA11'. This comparison revealed a close relationship between all eleven Eubacterium strains, forming three distinct clades: E. limosum, E. callanderi, and E. maltosivorans. Moreover, we identified the gene clusters responsible for methanol utilization as well as genes mediating chain elongation in all analyzed strains. Subsequent growth experiments revealed that strains of all three clades can convert methanol and produce acetate, butyrate, and hexanoate via reverse β-oxidation. Additionally, we used a harmonized electroporation protocol and successfully transformed eight of these Eubacterium strains to enable recombinant plasmid-based expression of the gene encoding the fluorescence-activating and absorption shifting tag (FAST). Engineered Eubacterium strains were verified regarding their FAST-mediated fluorescence at a single-cell level using a flow cytometry approach. Eventually, strains 'FD' (DSM 3662T), '2A' (DSM 2593), '11A' (DSM 2594), and '32' (DSM 20517) were genetically engineered for the first time. CONCLUSION Strains of E. limosum, E. callanderi, and E. maltosivorans are outstanding candidates as biocatalysts for anaerobic C1-substrate conversion into valuable biocommodities. A large variety of strains is genetically accessible using a harmonized electroporation protocol, and FAST can serve as a reliable fluorescent reporter protein to characterize genetically engineered cells. In total eleven strains have been assigned to distinct clades, providing a clear and updated classification. Thus, the description of respective Eubacterium species has been emended, improved, aligned, and is requested to be implemented in respective databases.
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Affiliation(s)
- Maximilian Flaiz
- Laboratory of Microbiology, Wageningen University and Research, Wageningen, The Netherlands.
- Institute of Microbiology and Biotechnology, University of Ulm, Ulm, Germany.
| | - Anja Poehlein
- Genomic and Applied Microbiology & Göttingen Genomics Laboratory, Georg-August University, Göttingen, Germany
| | - Wiebke Wilhelm
- Institute of Microbiology and Biotechnology, University of Ulm, Ulm, Germany
| | - Alexander Mook
- Institute of Molecular Biology and Biotechnology of Prokaryotes, University of Ulm, Ulm, Germany
| | - Rolf Daniel
- Genomic and Applied Microbiology & Göttingen Genomics Laboratory, Georg-August University, Göttingen, Germany
| | - Peter Dürre
- Institute of Microbiology and Biotechnology, University of Ulm, Ulm, Germany
| | - Frank R Bengelsdorf
- Institute of Molecular Biology and Biotechnology of Prokaryotes, University of Ulm, Ulm, Germany.
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Genome-wide CRISPRi screen identifies enhanced autolithotrophic phenotypes in acetogenic bacterium Eubacterium limosum. Proc Natl Acad Sci U S A 2023; 120:e2216244120. [PMID: 36716373 PMCID: PMC9963998 DOI: 10.1073/pnas.2216244120] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Acetogenic bacteria are a unique biocatalyst that highly promises to develop the sustainable bioconversion of carbon oxides (e.g., CO and CO2) into multicarbon biochemicals. Genotype-phenotype relationships are important for engineering their metabolic capability to enhance their biocatalytic performance; however, systemic investigation on the fitness contribution of individual gene has been limited. Here, we report genome-scale CRISPR interference screening using 41,939 guide RNAs designed from the E. limosum genome, one of the model acetogenic species, where all genes were targeted for transcriptional suppression. We investigated the fitness contributions of 96% of the total genes identified, revealing the gene fitness and essentiality for heterotrophic and autotrophic metabolisms. Our data show that the Wood-Ljungdahl pathway, membrane regeneration, membrane protein biosynthesis, and butyrate synthesis are essential for autotrophic acetogenesis in E. limosum. Furthermore, we discovered genes that are repression targets that unbiasedly increased autotrophic growth rates fourfold and acetoin production 1.5-fold compared to the wild-type strain under CO2-H2 conditions. These results provide insight for understanding acetogenic metabolism and genome engineering in acetogenic bacteria.
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Li QS, Wang R, Ma ZY, Zhang XM, Jiao JZ, Zhang ZG, Ungerfeld EM, Yi KL, Zhang BZ, Long L, Long Y, Tao Y, Huang T, Greening C, Tan ZL, Wang M. Dietary selection of metabolically distinct microorganisms drives hydrogen metabolism in ruminants. THE ISME JOURNAL 2022; 16:2535-2546. [PMID: 35931768 PMCID: PMC9562222 DOI: 10.1038/s41396-022-01294-9] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 06/29/2022] [Accepted: 07/11/2022] [Indexed: 11/09/2022]
Abstract
Ruminants are important for global food security but emit the greenhouse gas methane. Rumen microorganisms break down complex carbohydrates to produce volatile fatty acids and molecular hydrogen. This hydrogen is mainly converted into methane by archaea, but can also be used by hydrogenotrophic acetogenic and respiratory bacteria to produce useful metabolites. A better mechanistic understanding is needed on how dietary carbohydrates influence hydrogen metabolism and methanogenesis. We profiled the composition, metabolic pathways, and activities of rumen microbiota in 24 beef cattle adapted to either fiber-rich or starch-rich diets. The fiber-rich diet selected for fibrolytic bacteria and methanogens resulting in increased fiber utilization, while the starch-rich diet selected for amylolytic bacteria and lactate utilizers, allowing the maintenance of a healthy rumen and decreasing methane production (p < 0.05). Furthermore, the fiber-rich diet enriched for hydrogenotrophic methanogens and acetogens leading to increased electron-bifurcating [FeFe]-hydrogenases, methanogenic [NiFe]- and [Fe]-hydrogenases and acetyl-CoA synthase, with lower dissolved hydrogen (42%, p < 0.001). In contrast, the starch-rich diet enriched for respiratory hydrogenotrophs with greater hydrogen-producing group B [FeFe]-hydrogenases and respiratory group 1d [NiFe]-hydrogenases. Parallel in vitro experiments showed that the fiber-rich selected microbiome enhanced acetate and butyrate production while decreasing methane production (p < 0.05), suggesting that the enriched hydrogenotrophic acetogens converted some hydrogen that would otherwise be used by methanogenesis. These insights into hydrogen metabolism and methanogenesis improve understanding of energy harvesting strategies, healthy rumen maintenance, and methane mitigation in ruminants.
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Affiliation(s)
- Qiu Shuang Li
- Key Laboratory for Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, Hunan, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Rong Wang
- Key Laboratory for Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, Hunan, China
| | - Zhi Yuan Ma
- College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China
| | - Xiu Min Zhang
- Key Laboratory for Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, Hunan, China
| | - Jin Zhen Jiao
- Key Laboratory for Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, Hunan, China
| | - Zhi Gang Zhang
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, School of Life Sciences, Yunnan University, Kunming, Yunnan, China
| | - Emilio M Ungerfeld
- Centro Regional de Investigación Carillanca, Instituto de Investigaciones Agropecuarias (INIA), Temuco, Chile
| | - Kang Le Yi
- Hunan Institute of Animal and Veterinary Science, Changsha, Hunan, China
- Xiangxi Cattle Engineering Technology Center of Hunan Province, Huayuan, Hunan, China
| | - Bai Zhong Zhang
- Hunan Institute of Animal and Veterinary Science, Changsha, Hunan, China
- Xiangxi Cattle Engineering Technology Center of Hunan Province, Huayuan, Hunan, China
| | - Liang Long
- Xiangxi Cattle Engineering Technology Center of Hunan Province, Huayuan, Hunan, China
- Hunan De Nong Animal Husbandry Group Co. Ltd, Huayuan, Hunan, China
| | - Yun Long
- Xiangxi Cattle Engineering Technology Center of Hunan Province, Huayuan, Hunan, China
- Hunan De Nong Animal Husbandry Group Co. Ltd, Huayuan, Hunan, China
| | - Ye Tao
- Shanghai BIOZERON Biotechnology Company Ltd, Shanghai, China
| | - Tao Huang
- Shanghai Institute of Nutrition and Health, Chinese Academy of Sciences, Shanghai, China
| | - Chris Greening
- Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, Australia
| | - Zhi Liang Tan
- Key Laboratory for Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, Hunan, China.
- University of Chinese Academy of Sciences, Beijing, China.
| | - Min Wang
- Key Laboratory for Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, Hunan, China.
- University of Chinese Academy of Sciences, Beijing, China.
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Pregnon G, Minton NP, Soucaille P. Genome Sequence of Eubacterium limosum B2 and Evolution for Growth on a Mineral Medium with Methanol and CO2 as Sole Carbon Sources. Microorganisms 2022; 10:microorganisms10091790. [PMID: 36144392 PMCID: PMC9503626 DOI: 10.3390/microorganisms10091790] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 08/23/2022] [Accepted: 09/01/2022] [Indexed: 11/16/2022] Open
Abstract
Eubacterium limosum is an acetogen that can produce butyrate along with acetate as the main fermentation end-product from methanol, a promising C1 feedstock. Although physiological characterization of E. limosum B2 during methylotrophy was previously performed, the strain was cultured in a semi-defined medium, limiting the scope for further metabolic insights. Here, we sequenced the complete genome of the native strain and performed adaptive laboratory evolution to sustain growth on methanol mineral medium. The evolved population significantly improved its maximal growth rate by 3.45-fold. Furthermore, three clones from the evolved population were isolated on methanol mineral medium without cysteine by the addition of sodium thiosulfate. To identify mutations related to growth improvement, the whole genomes of wild-type E. limosum B2, the 10th, 25th, 50th, and 75th generations, and the three clones were sequenced. We explored the total proteomes of the native and the best evolved clone (n°2) and noticed significant differences in proteins involved in gluconeogenesis, anaplerotic reactions, and sulphate metabolism. Furthermore, a homologous recombination was found in subunit S of the type I restriction-modification system between both strains, changing the structure of the subunit, its sequence recognition and the methylome of the evolved clone. Taken together, the genomic, proteomic and methylomic data suggest a possible epigenetic mechanism of metabolic regulation.
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Affiliation(s)
- Guillaume Pregnon
- INSA, UPS, INP, Toulouse Biotechnology Institute (TBI), Université de Toulouse, 31400 Toulouse, France
| | - Nigel P. Minton
- BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, University Park, The University of Nottingham, Nottingham NG7 2RD, UK
| | - Philippe Soucaille
- INSA, UPS, INP, Toulouse Biotechnology Institute (TBI), Université de Toulouse, 31400 Toulouse, France
- BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, University Park, The University of Nottingham, Nottingham NG7 2RD, UK
- Correspondence: ; Tel.: +33-(0)-561-559-452
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Sanford PA, Woolston BM. Expanding the genetic engineering toolbox for the metabolically flexible acetogen Eubacterium limosum. J Ind Microbiol Biotechnol 2022; 49:6650221. [PMID: 35881468 PMCID: PMC9559302 DOI: 10.1093/jimb/kuac019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 06/30/2022] [Indexed: 11/14/2022]
Abstract
Acetogenic bacteria are an increasingly popular choice for producing fuels and chemicals from single carbon (C1) substrates. Eubacterium limosum is a promising acetogen with several native advantages, including the ability to catabolize a wide repertoire of C1 feedstocks and the ability to grow well on agar plates. However, despite its promise as a strain for synthetic biology and metabolic engineering, there are insufficient engineering tools and molecular biology knowledge to leverage its native strengths for these applications. To capitalize on the natural advantages of this organism, here we extended its limited engineering toolbox. We evaluated the copy number of three common plasmid origins of replication and devised a method of controlling copy number and heterologous gene expression level by modulating antibiotic concentration. We further quantitatively assessed the strength and regulatory tightness of a panel of promoters, developing a series of well-characterized vectors for gene expression at varying levels. In addition, we developed a black/white colorimetric genetic reporter assay and leveraged the high oxygen tolerance of E. limosum to develop a simple and rapid transformation protocol that enables benchtop transformation. Finally, we developed two new antibiotic selection markers—doubling the number available for this organism. These developments will enable enhanced metabolic engineering and synthetic biology work with E. limosum.
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Affiliation(s)
- Patrick A Sanford
- Department of Chemical Engineering, Northeastern University, 360 Huntington Avenue, 223 Cullinane, Boston, MA 02115, USA
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9
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Rich BE, Jackson JC, de Ora LO, Long ZG, Uyeda KS, Bess EN. Alternative pathway for dopamine production by acetogenic gut bacteria that O-Demethylate 3-Methoxytyramine, a metabolite of catechol O-Methyltransferase. J Appl Microbiol 2022; 133:1697-1708. [PMID: 35737746 PMCID: PMC9544265 DOI: 10.1111/jam.15682] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 06/01/2022] [Accepted: 06/20/2022] [Indexed: 11/27/2022]
Abstract
AIMS The gut microbiota modulates dopamine levels in vivo, but the bacteria and biochemical processes responsible remain incompletely characterized. A potential precursor of bacterial dopamine production is 3-methoxytyramine (3MT); 3MT is produced when dopamine is O-methylated by host catechol O-methyltransferase (COMT), thereby attenuating dopamine levels. This study aimed to identify whether gut bacteria are capable of reverting 3MT to dopamine. METHODS AND RESULTS Human faecal bacterial communities O-demethylated 3MT and yielded dopamine. Gut bacteria that mediate this transformation were identified as acetogens Eubacterium limosum and Blautia producta. Upon exposing these acetogens to propyl iodide, a known inhibitor of cobalamin-dependent O-demethylases, 3MT O-demethylation was inhibited. Culturing E. limosum and B. producta with 3MT afforded increased acetate levels as compared with vehicle controls. CONCLUSIONS Gut bacterial acetogens E. limosum and B. producta synthesized dopamine from 3MT. This O-demethylation of 3MT was likely performed by cobalamin-dependent O-demethylases implicated in reductive acetogenesis. SIGNIFICANCE AND IMPACT OF THE STUDY This is the first report that gut bacteria can synthesize dopamine by O-demethylation of 3MT. Owing to 3MT being the product of host COMT attenuating dopamine levels, gut bacteria that reverse this transformation-converting 3MT to dopamine-may act as a counterbalance for dopamine regulation by COMT.
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Affiliation(s)
- Barry E Rich
- Department of Chemistry, University of California, Irvine, Irvine, California, USA
| | - Jayme C Jackson
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, California, USA
| | - Lizett Ortiz de Ora
- Department of Chemistry, University of California, Irvine, Irvine, California, USA
| | - Zane G Long
- Department of Chemistry, University of California, Irvine, Irvine, California, USA
| | - Kylie S Uyeda
- Department of Chemistry, University of California, Irvine, Irvine, California, USA
| | - Elizabeth N Bess
- Department of Chemistry, University of California, Irvine, Irvine, California, USA.,Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, California, USA
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Karekar S, Stefanini R, Ahring B. Homo-Acetogens: Their Metabolism and Competitive Relationship with Hydrogenotrophic Methanogens. Microorganisms 2022; 10:microorganisms10020397. [PMID: 35208852 PMCID: PMC8875654 DOI: 10.3390/microorganisms10020397] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 02/01/2022] [Accepted: 02/02/2022] [Indexed: 12/04/2022] Open
Abstract
Homo-acetogens are microbes that have the ability to grow on gaseous substrates such as H2/CO2/CO and produce acetic acid as the main product of their metabolism through a metabolic process called reductive acetogenesis. These acetogens are dispersed in nature and are found to grow in various biotopes on land, water and sediments. They are also commonly found in the gastro-intestinal track of herbivores that rely on a symbiotic relationship with microbes in order to breakdown lignocellulosic biomass to provide the animal with nutrients and energy. For this motive, the fermentation scheme that occurs in the rumen has been described equivalent to a consolidated bioprocessing fermentation for the production of bioproducts derived from livestock. This paper reviews current knowledge of homo-acetogenesis and its potential to improve efficiency in the rumen for production of bioproducts by replacing methanogens, the principal H2-scavengers in the rumen, thus serving as a form of carbon sink by deviating the formation of methane into bioproducts. In this review, we discuss the main strategies employed by the livestock industry to achieve methanogenesis inhibition, and also explore homo-acetogenic microorganisms and evaluate the members for potential traits and characteristics that may favor competitive advantage over methanogenesis, making them prospective candidates for competing with methanogens in ruminant animals.
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Affiliation(s)
- Supriya Karekar
- Bioproducts Science and Engineering Laboratory, Washington State University Tri-Cities, 2720 Crimson Way, Richland, WA 99354, USA; (S.K.); (R.S.)
- Department of Biological Systems Engineering, Washington State University, Pullman, WA 99163, USA
| | - Renan Stefanini
- Bioproducts Science and Engineering Laboratory, Washington State University Tri-Cities, 2720 Crimson Way, Richland, WA 99354, USA; (S.K.); (R.S.)
- Department of Biological Systems Engineering, Washington State University, Pullman, WA 99163, USA
| | - Birgitte Ahring
- Bioproducts Science and Engineering Laboratory, Washington State University Tri-Cities, 2720 Crimson Way, Richland, WA 99354, USA; (S.K.); (R.S.)
- Department of Biological Systems Engineering, Washington State University, Pullman, WA 99163, USA
- The Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA 99163, USA
- Correspondence:
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11
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Sheridan PO, Louis P, Tsompanidou E, Shaw S, Harmsen HJ, Duncan SH, Flint HJ, Walker AW. Distribution, organization and expression of genes concerned with anaerobic lactate utilization in human intestinal bacteria. Microb Genom 2022; 8. [PMID: 35077342 PMCID: PMC8914356 DOI: 10.1099/mgen.0.000739] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Lactate accumulation in the human gut is linked to a range of deleterious health impacts. However, lactate is consumed and converted to the beneficial short-chain fatty acids butyrate and propionate by indigenous lactate-utilizing bacteria. To better understand the underlying genetic basis for lactate utilization, transcriptomic analyses were performed for two prominent lactate-utilizing species from the human gut, Anaerobutyricum soehngenii and Coprococcus catus, during growth on lactate, hexose sugar or hexose plus lactate. In A. soehngenii L2-7 six genes of the lactate utilization (lct) cluster, including NAD-independent d-lactate dehydrogenase (d-iLDH), were co-ordinately upregulated during growth on equimolar d- and l-lactate (dl-lactate). Upregulated genes included an acyl-CoA dehydrogenase related to butyryl-CoA dehydrogenase, which may play a role in transferring reducing equivalents between reduction of crotonyl-CoA and oxidation of lactate. Genes upregulated in C. catus GD/7 included a six-gene cluster (lap) encoding propionyl CoA-transferase, a putative lactoyl-CoA epimerase, lactoyl-CoA dehydratase and lactate permease, and two unlinked acyl-CoA dehydrogenase genes that are candidates for acryloyl-CoA reductase. A d-iLDH homologue in C. catus is encoded by a separate, partial lct, gene cluster, but not upregulated on lactate. While C. catus converts three mols of dl-lactate via the acrylate pathway to two mols propionate and one mol acetate, some of the acetate can be re-used with additional lactate to produce butyrate. A key regulatory difference is that while glucose partially repressed lct cluster expression in A. soehngenii, there was no repression of lactate-utilization genes by fructose in the non-glucose utilizer C. catus. This suggests that these species could occupy different ecological niches for lactate utilization in the gut, which may be important factors to consider when developing lactate-utilizing bacteria as novel candidate probiotics.
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Affiliation(s)
- Paul O Sheridan
- Gut Health Group, Rowett Institute, University of Aberdeen, Foresterhill, AB25 2ZD Aberdeen, UK
| | - Petra Louis
- Gut Health Group, Rowett Institute, University of Aberdeen, Foresterhill, AB25 2ZD Aberdeen, UK
| | - Eleni Tsompanidou
- Medical Microbiology and Infection Prevention, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands
| | - Sophie Shaw
- Centre for Genome-Enabled Biology and Medicine, 23 St. Machar Drive, AB24 3RY Aberdeen, UK
| | - Hermie J Harmsen
- Medical Microbiology and Infection Prevention, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands
| | - Sylvia H Duncan
- Gut Health Group, Rowett Institute, University of Aberdeen, Foresterhill, AB25 2ZD Aberdeen, UK
| | - Harry J Flint
- Gut Health Group, Rowett Institute, University of Aberdeen, Foresterhill, AB25 2ZD Aberdeen, UK
| | - Alan W Walker
- Gut Health Group, Rowett Institute, University of Aberdeen, Foresterhill, AB25 2ZD Aberdeen, UK
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12
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Feng Y, Bui TPN, Stams AJM, Boeren S, Sánchez-Andrea I, de Vos WM. Comparative genomics and proteomics of Eubacterium maltosivorans: functional identification of trimethylamine methyltransferases and bacterial microcompartments in a human intestinal bacterium with a versatile lifestyle. Environ Microbiol 2022; 24:517-534. [PMID: 34978130 PMCID: PMC9303578 DOI: 10.1111/1462-2920.15886] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 12/01/2021] [Accepted: 12/21/2021] [Indexed: 12/14/2022]
Abstract
Eubacterium maltosivorans YIT is a human intestinal isolate capable of acetogenic, propionogenic and butyrogenic growth. Its 4.3-Mb genome sequence contains coding sequences for 4227 proteins, including 41 different methyltransferases. Comparative proteomics of strain YIT showed the Wood-Ljungdahl pathway proteins to be actively produced during homoacetogenic growth on H2 and CO2 while butyrogenic growth on a mixture of lactate and acetate significantly upregulated the production of proteins encoded by the recently identified lctABCDEF cluster and accessory proteins. Growth on H2 and CO2 unexpectedly induced the production of two related trimethylamine methyltransferases. Moreover, a set of 16 different trimethylamine methyltransferases together with proteins for bacterial microcompartments were produced during growth and deamination of the quaternary amines, betaine, carnitine and choline. Growth of strain YIT on 1,2-propanediol generated propionate with propanol and induced the formation of bacterial microcompartments that were also prominently visible in betaine-grown cells. The present study demonstrates that E. maltosivorans is highly versatile in converting low-energy fermentation end-products in the human gut into butyrate and propionate whilst being capable of preventing the formation of the undesired trimethylamine by converting betaine and other quaternary amines in bacterial microcompartments into acetate and butyrate.
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Affiliation(s)
- Yuan Feng
- Laboratory of Microbiology, Wageningen University and Research, Stippeneng 4, Wageningen, 6708 WE, The Netherlands
| | - Thi Phuong Nam Bui
- Laboratory of Microbiology, Wageningen University and Research, Stippeneng 4, Wageningen, 6708 WE, The Netherlands.,Caelus Pharmaceuticals, Amsterdam, The Netherlands
| | - Alfons J M Stams
- Laboratory of Microbiology, Wageningen University and Research, Stippeneng 4, Wageningen, 6708 WE, The Netherlands.,Centre of Biological Engineering, IBB - Institute for Biotechnology and Bioengineering, University of Minho, Campus de Gualtar, Braga, 4710-057, Portugal
| | - Sjef Boeren
- Laboratory of Biochemistry, Wageningen University and Research, Stippeneng 4, Wageningen, 6708 WE, The Netherlands
| | - Irene Sánchez-Andrea
- Laboratory of Microbiology, Wageningen University and Research, Stippeneng 4, Wageningen, 6708 WE, The Netherlands
| | - Willem M de Vos
- Laboratory of Microbiology, Wageningen University and Research, Stippeneng 4, Wageningen, 6708 WE, The Netherlands.,Human Microbiome Research Program, Faculty of Medicine, University of Helsinki, Helsinki, 00014, Finland
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13
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Biological conversion of carbon monoxide and hydrogen by anaerobic culture: Prospect of anaerobic digestion and thermochemical processes combination. Biotechnol Adv 2021; 58:107886. [PMID: 34915147 DOI: 10.1016/j.biotechadv.2021.107886] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 11/26/2021] [Accepted: 12/08/2021] [Indexed: 01/04/2023]
Abstract
Waste biomass is considered a promising renewable energy feedstock that can be converted by anaerobic digestion. However, anaerobic digestion application can be challenging due to the structural complexity of several waste biomass kinds. Therefore, coupling anaerobic digestion with thermochemical processes can offset the limitations and convert the hardly biodegradable waste biomass, including digestate residue, into value-added products: syngas and pyrogas (gaseous mixtures consisting mainly of H2, CO, CO2), bio-oil, and biochar for further valorisation. In this review, the utilisation boundaries and benefits of the aforementioned products by anaerobic culture are discussed. First, thermochemical process parameters for an enhanced yield of desired products are summarised. Particularly, the microbiology of CO and H2 mixture biomethanation and fermentation in anaerobic digestion is presented. Finally, the state-of-the-art biological conversion of syngas and pyrogas to CH4 mediated by anaerobic culture is adequately described. Extensive research shows the successful selective biological conversion of CO and H2 to CH4, acetic acid, and alcohols. The main bottleneck is the gas-liquid mass transfer which can be enhanced appropriately by bioreactors' configurations. A few research groups focus on bio-oil and biochar addition into anaerobic digesters. However, according to the literature review, there has been no research for utilising all value-added products at once in anaerobic digestion published so far. Although synergic effects of such can be expected. In summary, the combination of anaerobic digestion and thermochemical processes is a promising alternative for wide-scale waste biomass utilisation in practice.
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14
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Kremp F, Müller V. Methanol and methyl group conversion in acetogenic bacteria: biochemistry, physiology and application. FEMS Microbiol Rev 2021; 45:5903270. [PMID: 32901799 DOI: 10.1093/femsre/fuaa040] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 08/29/2020] [Indexed: 12/24/2022] Open
Abstract
The production of bulk chemicals mostly depends on exhausting petroleum sources and leads to emission of greenhouse gases. Within the last decades the urgent need for alternative sources has increased and the development of bio-based processes received new attention. To avoid the competition between the use of sugars as food or fuel, other feedstocks with high availability and low cost are needed, which brought acetogenic bacteria into focus. This group of anaerobic organisms uses mixtures of CO2, CO and H2 for the production of mostly acetate and ethanol. Also methanol, a cheap and abundant bulk chemical produced from methane, is a suitable substrate for acetogenic bacteria. In methylotrophic acetogens the methyl group is transferred to the Wood-Ljungdahl pathway, a pathway to reduce CO2 to acetate via a series of C1-intermediates bound to tetrahydrofolic acid. Here we describe the biochemistry and bioenergetics of methanol conversion in the biotechnologically interesting group of anaerobic, acetogenic bacteria. Further, the bioenergetics of biochemical production from methanol is discussed.
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Affiliation(s)
- Florian Kremp
- Department of Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe University, Max-von-Laue Str. 9, D-60438 Frankfurt, Germany
| | - Volker Müller
- Department of Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe University, Max-von-Laue Str. 9, D-60438 Frankfurt, Germany
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15
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Bourgade B, Minton NP, Islam MA. Genetic and metabolic engineering challenges of C1-gas fermenting acetogenic chassis organisms. FEMS Microbiol Rev 2021; 45:fuab008. [PMID: 33595667 PMCID: PMC8351756 DOI: 10.1093/femsre/fuab008] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 01/15/2021] [Indexed: 12/11/2022] Open
Abstract
Unabated mining and utilisation of petroleum and petroleum resources and their conversion to essential fuels and chemicals have drastic environmental consequences, contributing to global warming and climate change. In addition, fossil fuels are finite resources, with a fast-approaching shortage. Accordingly, research efforts are increasingly focusing on developing sustainable alternatives for chemicals and fuels production. In this context, bioprocesses, relying on microorganisms, have gained particular interest. For example, acetogens use the Wood-Ljungdahl pathway to grow on single carbon C1-gases (CO2 and CO) as their sole carbon source and produce valuable products such as acetate or ethanol. These autotrophs can, therefore, be exploited for large-scale fermentation processes to produce industrially relevant chemicals from abundant greenhouse gases. In addition, genetic tools have recently been developed to improve these chassis organisms through synthetic biology approaches. This review will focus on the challenges of genetically and metabolically modifying acetogens. It will first discuss the physical and biochemical obstacles complicating successful DNA transfer in these organisms. Current genetic tools developed for several acetogens, crucial for strain engineering to consolidate and expand their catalogue of products, will then be described. Recent tool applications for metabolic engineering purposes to allow redirection of metabolic fluxes or production of non-native compounds will lastly be covered.
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Affiliation(s)
- Barbara Bourgade
- Department of Chemical Engineering, Loughborough University, Loughborough, Leicestershire, LE11 3TU, UK
| | - Nigel P Minton
- BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, University Park, University of Nottingham, Nottingham, Nottinghamshire, NG7 2RD, UK
| | - M Ahsanul Islam
- Department of Chemical Engineering, Loughborough University, Loughborough, Leicestershire, LE11 3TU, UK
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16
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Shin J, Kang S, Song Y, Jin S, Lee JS, Lee JK, Kim DR, Kim SC, Cho S, Cho BK. Genome Engineering of Eubacterium limosum Using Expanded Genetic Tools and the CRISPR-Cas9 System. ACS Synth Biol 2019; 8:2059-2068. [PMID: 31373788 DOI: 10.1021/acssynbio.9b00150] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Eubacterium limosum is one of the important bacteria in C1 feedstock utilization as well as in human gut microbiota. Although E. limosum has recently garnered much attention and investigation on a genome-wide scale, a bottleneck for systematic engineering in E. limosum is the lack of available genetic tools and an efficient genome editing platform. To overcome this limitation, we here report expanded genetic tools and the CRISPR-Cas9 system. We have developed an inducible promoter system that enables implementation of the CRISPR-Cas9 system to precisely manipulate target genes of the Wood-Ljungdahl pathway with 100% efficiency. Furthermore, we exploited the effectiveness of CRISPR interference to reduce the expression of target genes, exhibiting substantial repression of several genes in the Wood-Ljungdahl pathway and fructose-PTS system. These expanded genetic tools and CRISPR-Cas9 system comprise powerful and widely applicable genetic tools to accelerate functional genomic study and genome engineering in E. limosum.
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Affiliation(s)
- Jongoh Shin
- Department of Biological Sciences and KI for the BioCentury , KAIST , Daejeon , 305-701 , Republic of Korea
| | - Seulgi Kang
- Department of Biological Sciences and KI for the BioCentury , KAIST , Daejeon , 305-701 , Republic of Korea
| | - Yoseb Song
- Department of Biological Sciences and KI for the BioCentury , KAIST , Daejeon , 305-701 , Republic of Korea
| | - Sangrak Jin
- Department of Biological Sciences and KI for the BioCentury , KAIST , Daejeon , 305-701 , Republic of Korea
| | - Jin Soo Lee
- Department of Biological Sciences and KI for the BioCentury , KAIST , Daejeon , 305-701 , Republic of Korea
| | - Jung-Kul Lee
- Department of Chemical Engineering , Konkuk University , Seoul , 05029 , Republic of Korea
| | - Dong Rip Kim
- Department of Mechanical Engineering , Hanyang University , Seoul , 04763 , Republic of Korea
| | - Sun Chang Kim
- Department of Biological Sciences and KI for the BioCentury , KAIST , Daejeon , 305-701 , Republic of Korea
- Intelligent Synthetic Biology Center , Daejeon , 305-701 , Republic of Korea
| | - Suhyung Cho
- Department of Biological Sciences and KI for the BioCentury , KAIST , Daejeon , 305-701 , Republic of Korea
| | - Byung-Kwan Cho
- Department of Biological Sciences and KI for the BioCentury , KAIST , Daejeon , 305-701 , Republic of Korea
- Intelligent Synthetic Biology Center , Daejeon , 305-701 , Republic of Korea
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17
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Oliphant K, Allen-Vercoe E. Macronutrient metabolism by the human gut microbiome: major fermentation by-products and their impact on host health. MICROBIOME 2019; 7:91. [PMID: 31196177 PMCID: PMC6567490 DOI: 10.1186/s40168-019-0704-8] [Citation(s) in RCA: 767] [Impact Index Per Article: 127.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Accepted: 05/28/2019] [Indexed: 05/11/2023]
Abstract
The human gut microbiome is a critical component of digestion, breaking down complex carbohydrates, proteins, and to a lesser extent fats that reach the lower gastrointestinal tract. This process results in a multitude of microbial metabolites that can act both locally and systemically (after being absorbed into the bloodstream). The impact of these biochemicals on human health is complex, as both potentially beneficial and potentially toxic metabolites can be yielded from such microbial pathways, and in some cases, these effects are dependent upon the metabolite concentration or organ locality. The aim of this review is to summarize our current knowledge of how macronutrient metabolism by the gut microbiome influences human health. Metabolites to be discussed include short-chain fatty acids and alcohols (mainly yielded from monosaccharides); ammonia, branched-chain fatty acids, amines, sulfur compounds, phenols, and indoles (derived from amino acids); glycerol and choline derivatives (obtained from the breakdown of lipids); and tertiary cycling of carbon dioxide and hydrogen. Key microbial taxa and related disease states will be referred to in each case, and knowledge gaps that could contribute to our understanding of overall human wellness will be identified.
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Affiliation(s)
- Kaitlyn Oliphant
- Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Rd E, Guelph, ON N1G 2W1 Canada
| | - Emma Allen-Vercoe
- Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Rd E, Guelph, ON N1G 2W1 Canada
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18
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Abstract
Hydrogen plays a key role in many microbial metabolic pathways in the human gastrointestinal tract (GIT) that have an impact on human nutrition, health and wellbeing. Hydrogen is produced by many members of the GIT microbiota, and may be subsequently utilized by cross-feeding microbes for growth and in the production of larger molecules. Hydrogenotrophic microbes fall into three functional groups: sulfate-reducing bacteria, methanogenic archaea and acetogenic bacteria, which can convert hydrogen into hydrogen sulfide, methane and acetate, respectively. Despite different energy yields per molecule of hydrogen used between the functional groups, all three can coexist in the human GIT. The factors affecting the numerical balance of hydrogenotrophs in the GIT remain unconfirmed. There is increasing evidence linking both hydrogen sulfide and methane to GIT diseases such as irritable bowel syndrome, and strategies for the mitigation of such health problems through targeting of hydrogenotrophs constitute an important field for further investigation.
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Affiliation(s)
- Nick W. Smith
- AgResearch, Ruakura Research Centre, Hamilton, New Zealand,AgResearch, Grasslands Research Centre, Palmerston North, New Zealand,Riddet Institute, Massey University, Palmerston North, New Zealand
| | - Paul R. Shorten
- AgResearch, Ruakura Research Centre, Hamilton, New Zealand,Riddet Institute, Massey University, Palmerston North, New Zealand,CONTACT Paul R. Shorten AgResearch, Ruakura Research Centre, Private Bag 3123, Hamilton 3240, New Zealand
| | - Eric H. Altermann
- AgResearch, Grasslands Research Centre, Palmerston North, New Zealand,Riddet Institute, Massey University, Palmerston North, New Zealand
| | - Nicole C. Roy
- AgResearch, Grasslands Research Centre, Palmerston North, New Zealand,Riddet Institute, Massey University, Palmerston North, New Zealand,High-Value Nutrition National Science Challenge, hosted by The University of Auckland, Auckland, New Zealand
| | - Warren C. McNabb
- Riddet Institute, Massey University, Palmerston North, New Zealand
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19
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Feng Y, Stams AJM, Sánchez-Andrea I, de Vos WM. Eubacterium maltosivorans sp. nov., a novel human intestinal acetogenic and butyrogenic bacterium with a versatile metabolism. Int J Syst Evol Microbiol 2018; 68:3546-3550. [PMID: 30285910 DOI: 10.1099/ijsem.0.003028] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A novel anaerobic, non-spore-forming bacterium was isolated from a faecal sample of a healthy adult. The isolate, designated strain YIT, was cultured in a basal liquid medium under a gas phase of H2/CO2 supplemented with yeast extract (0.1 g l-1). Cells of strain YIT were short rods (0.4-0.7×2.0-2.5 µm), appearing singly or in pairs, and stained Gram-positive. Catalase activity and gelatin hydrolysis were positive while oxidase activity, indole formation, urease activity and aesculin hydrolysis were negative. Growth was observed within a temperature range of 20-45 °C (optimum, 35-37 °C), and a pH range of 5.0-8.0 (optimum pH 7.0-7.5). Doubling time was 2.3 h when grown with glucose at pH 7.2 and 37 °C. Besides acetogenic growth, the isolate was able to ferment a large range of monomeric sugars with acetate and butyrate as the main end products. Strain YIT did not show respiratory growth with sulfate, sulfite, thiosulfate or nitrate as electron acceptors. The major cellular fatty acids of the isolate were C16 : 0 and C18 : 0. The genomic DNA G+C content was 47.8 mol%. Strain YIT is affiliated to the genus Eubacterium, sharing highest levels of 16S rRNA gene similarity with Eubacterium limosum ATCC 8486T (97.3 %), Eubacterium callanderi DSM 3662T (97.5 %), Eubacterium aggregans DSM 12183T (94.4 %) and Eubacterium barkeri DSM 1223T (94.8 %). Considering its physiological and phylogenetic characteristics, strain YIT represents a novel species within the genus Eubacterium, for which the name Eubacterium maltosivorans sp. nov. is proposed. The type strain is YIT (=DSM 105863T=JCM 32297T).
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Affiliation(s)
- Yuan Feng
- 1Laboratory of Microbiology, Wageningen University, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Alfons J M Stams
- 2IBB - Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057, Braga, Portugal
- 1Laboratory of Microbiology, Wageningen University, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Irene Sánchez-Andrea
- 1Laboratory of Microbiology, Wageningen University, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Willem M de Vos
- 3RPU Immunobiology, Department of Bacteriology and Immunology, Faculty of Medicine, University of Helsinki, 00014 Helsinki, Finland
- 1Laboratory of Microbiology, Wageningen University, Stippeneng 4, 6708 WE Wageningen, The Netherlands
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20
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Wirth R, Kádár G, Kakuk B, Maróti G, Bagi Z, Szilágyi Á, Rákhely G, Horváth J, Kovács KL. The Planktonic Core Microbiome and Core Functions in the Cattle Rumen by Next Generation Sequencing. Front Microbiol 2018; 9:2285. [PMID: 30319585 PMCID: PMC6165872 DOI: 10.3389/fmicb.2018.02285] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 09/07/2018] [Indexed: 12/31/2022] Open
Abstract
The cow rumen harbors a great variety of diverse microbes, which form a complex, organized community. Understanding the behavior of this multifarious network is crucial in improving ruminant nutrient use efficiency. The aim of this study was to expand our knowledge by examining 10 Holstein dairy cow rumen fluid fraction whole metagenome and transcriptome datasets. DNA and mRNA sequence data, generated by Ion Torrent, was subjected to quality control and filtering before analysis for core elements. The taxonomic core microbiome consisted of 48 genera belonging to Bacteria (47) and Archaea (1). The genus Prevotella predominated the planktonic core community. Core functional groups were identified using co-occurrence analysis and resulted in 587 genes, from which 62 could be assigned to metabolic functions. Although this was a minimal functional core, it revealed key enzymes participating in various metabolic processes. A diverse and rich collection of enzymes involved in carbohydrate metabolism and other functions were identified. Transcripts coding for enzymes active in methanogenesis made up 1% of the core functions. The genera associated with the core enzyme functions were also identified. Linking genera to functions showed that the main metabolic pathways are primarily provided by Bacteria and several genera may serve as a “back-up” team for the central functions. The key actors in most essential metabolic routes belong to the genus Prevotella. Confirming earlier studies, the genus Methanobrevibacter carries out the overwhelming majority of rumen methanogenesis and therefore methane emission mitigation seems conceivable via targeting the hydrogenotrophic methanogenesis.
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Affiliation(s)
- Roland Wirth
- Department of Biotechnology, University of Szeged, Szeged, Hungary
| | | | - Balázs Kakuk
- Department of Biotechnology, University of Szeged, Szeged, Hungary
| | - Gergely Maróti
- Institute of Plant Biology, Biological Research Center, Hungarian Academy of Sciences, Szeged, Hungary
| | - Zoltán Bagi
- Department of Biotechnology, University of Szeged, Szeged, Hungary
| | - Árpád Szilágyi
- Department of Biotechnology, University of Szeged, Szeged, Hungary
| | - Gábor Rákhely
- Department of Biotechnology, University of Szeged, Szeged, Hungary.,Institute of Biophysics, Biological Research Center, Hungarian Academy of Sciences, Szeged, Hungary
| | - József Horváth
- Faculty of Agriculture, University of Szeged, Hódmezövásárhely, Hungary
| | - Kornél L Kovács
- Department of Biotechnology, University of Szeged, Szeged, Hungary.,Institute of Biophysics, Biological Research Center, Hungarian Academy of Sciences, Szeged, Hungary.,Department of Oral Biology and Experimental Dental Research, University of Szeged, Szeged, Hungary
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21
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Bengelsdorf FR, Beck MH, Erz C, Hoffmeister S, Karl MM, Riegler P, Wirth S, Poehlein A, Weuster-Botz D, Dürre P. Bacterial Anaerobic Synthesis Gas (Syngas) and CO 2+H 2 Fermentation. ADVANCES IN APPLIED MICROBIOLOGY 2018; 103:143-221. [PMID: 29914657 DOI: 10.1016/bs.aambs.2018.01.002] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Anaerobic bacterial gas fermentation gains broad interest in various scientific, social, and industrial fields. This microbial process is carried out by a specific group of bacterial strains called acetogens. All these strains employ the Wood-Ljungdahl pathway but they belong to different taxonomic groups. Here we provide an overview of the metabolism of acetogens and naturally occurring products. Characteristics of 61 strains were summarized and selected acetogens described in detail. Acetobacterium woodii, Clostridium ljungdahlii, and Moorella thermoacetica serve as model organisms. Results of approaches such as genome-scale modeling, proteomics, and transcriptomics are discussed. Metabolic engineering of acetogens can be used to expand the product portfolio to platform chemicals and to study different aspects of cell physiology. Moreover, the fermentation of gases requires specific reactor configurations and the development of the respective technology, which can be used for an industrial application. Even though the overall process will have a positive effect on climate, since waste and greenhouse gases could be converted into commodity chemicals, some legislative barriers exist, which hamper successful exploitation of this technology.
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Affiliation(s)
- Frank R Bengelsdorf
- Institute of Microbiology and Biotechnology, University of Ulm, Ulm, Germany.
| | - Matthias H Beck
- Institute of Microbiology and Biotechnology, University of Ulm, Ulm, Germany
| | - Catarina Erz
- Institute of Microbiology and Biotechnology, University of Ulm, Ulm, Germany
| | - Sabrina Hoffmeister
- Institute of Microbiology and Biotechnology, University of Ulm, Ulm, Germany
| | - Michael M Karl
- Institute of Microbiology and Biotechnology, University of Ulm, Ulm, Germany
| | - Peter Riegler
- Technical University of Munich, Institute of Biochemical Engineering, Garching, Germany
| | - Steffen Wirth
- Institute of Microbiology and Biotechnology, University of Ulm, Ulm, Germany
| | - Anja Poehlein
- Genomic and Applied Microbiology & Göttingen Genomics Laboratory, Institute of Microbiology and Genetics, Georg-August University, Göttingen, Germany
| | - Dirk Weuster-Botz
- Technical University of Munich, Institute of Biochemical Engineering, Garching, Germany
| | - Peter Dürre
- Institute of Microbiology and Biotechnology, University of Ulm, Ulm, Germany
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Determination of the Genome and Primary Transcriptome of Syngas Fermenting Eubacterium limosum ATCC 8486. Sci Rep 2017; 7:13694. [PMID: 29057933 PMCID: PMC5651825 DOI: 10.1038/s41598-017-14123-3] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Accepted: 10/03/2017] [Indexed: 01/05/2023] Open
Abstract
Autotrophic conversion of CO2 to value-added biochemicals has received considerable attention as a sustainable route to replace fossil fuels. Particularly, anaerobic acetogenic bacteria are naturally capable of reducing CO2 or CO to various metabolites. To fully utilize their biosynthetic potential, an understanding of acetogenesis-related genes and their regulatory elements is required. Here, we completed the genome sequence of the syngas fermenting Eubacterium limosum ATCC 8486 and determined its transcription start sites (TSS). We constructed a 4.4 Mb long circular genome with a GC content of 47.2% and 4,090 protein encoding genes. To understand the transcriptional and translational regulation, the primary transcriptome was augmented, identifying 1,458 TSSs containing a high pyrimidine (T/C) and purine nucleotide (A/G) content at the −1 and +1 position, respectively, along with 1,253 5′-untranslated regions, and principal promoter elements such as −10 (TATAAT) and −35 (TTGACA), and Shine-Dalgarno motifs (GGAGR). Further analysis revealed 93 non-coding RNAs, including one for potential transcriptional regulation of the hydrogenase complex via interaction with molybdenum or tungsten cofactors, which in turn controls formate dehydrogenase activity of the initial step of Wood-Ljungdahl pathway. Our results provide comprehensive genomic information for strain engineering to enhance the syngas fermenting capacity of acetogenic bacteria.
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Poehlein A, Solano JDM, Flitsch SK, Krabben P, Winzer K, Reid SJ, Jones DT, Green E, Minton NP, Daniel R, Dürre P. Microbial solvent formation revisited by comparative genome analysis. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:58. [PMID: 28286553 PMCID: PMC5343299 DOI: 10.1186/s13068-017-0742-z] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2016] [Accepted: 02/28/2017] [Indexed: 05/04/2023]
Abstract
BACKGROUND Microbial formation of acetone, isopropanol, and butanol is largely restricted to bacteria belonging to the genus Clostridium. This ability has been industrially exploited over the last 100 years. The solvents are important feedstocks for the chemical and biofuel industry. However, biological synthesis suffers from high substrate costs and competition from chemical synthesis supported by the low price of crude oil. To render the biotechnological production economically viable again, improvements in microbial and fermentation performance are necessary. However, no comprehensive comparisons of respective species and strains used and their specific abilities exist today. RESULTS The genomes of a total 30 saccharolytic Clostridium strains, representative of the species Clostridium acetobutylicum, C. aurantibutyricum, C. beijerinckii, C. diolis, C. felsineum, C. pasteurianum, C. puniceum, C. roseum, C. saccharobutylicum, and C. saccharoperbutylacetonicum, have been determined; 10 of them completely, and compared to 14 published genomes of other solvent-forming clostridia. Two major groups could be differentiated and several misclassified species were detected. CONCLUSIONS Our findings represent a comprehensive study of phylogeny and taxonomy of clostridial solvent producers that highlights differences in energy conservation mechanisms and substrate utilization between strains, and allow for the first time a direct comparison of sequentially selected industrial strains at the genetic level. Detailed data mining is now possible, supporting the identification of new engineering targets for improved solvent production.
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Affiliation(s)
- Anja Poehlein
- Genomic and Applied Microbiology and Göttingen Genomics Laboratory, Georg-August University Göttingen, Grisebachstr. 8, 37077 Göttingen, Germany
| | - José David Montoya Solano
- Institut für Mikrobiologie und Biotechnologie, Universität Ulm, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Stefanie K. Flitsch
- Institut für Mikrobiologie und Biotechnologie, Universität Ulm, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Preben Krabben
- Green Biologics Ltd., 45A Western Avenue, Milton Park, Abingdon, Oxfordshire OX14 4RU UK
| | - Klaus Winzer
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, University of Nottingham, Nottingham, NG7 2RD UK
| | - Sharon J. Reid
- Department of Molecular and Cell Biology, University of Cape Town, Rondebosch, Cape Town, 7701 South Africa
| | - David T. Jones
- Department of Microbiology and Immunology, University of Otago, Dunedin, 9010 New Zealand
| | - Edward Green
- CHAIN Biotechnology Ltd., Imperial College Incubator, Level 1 Bessemer Building, Imperial College London, London, SW7 2AZ UK
| | - Nigel P. Minton
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, University of Nottingham, Nottingham, NG7 2RD UK
| | - Rolf Daniel
- Genomic and Applied Microbiology and Göttingen Genomics Laboratory, Georg-August University Göttingen, Grisebachstr. 8, 37077 Göttingen, Germany
| | - Peter Dürre
- Institut für Mikrobiologie und Biotechnologie, Universität Ulm, Albert-Einstein-Allee 11, 89081 Ulm, Germany
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Shin J, Song Y, Jeong Y, Cho BK. Analysis of the Core Genome and Pan-Genome of Autotrophic Acetogenic Bacteria. Front Microbiol 2016; 7:1531. [PMID: 27733845 PMCID: PMC5039349 DOI: 10.3389/fmicb.2016.01531] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 09/12/2016] [Indexed: 01/07/2023] Open
Abstract
Acetogens are obligate anaerobic bacteria capable of reducing carbon dioxide (CO2) to multicarbon compounds coupled to the oxidation of inorganic substrates, such as hydrogen (H2) or carbon monoxide (CO), via the Wood-Ljungdahl pathway. Owing to the metabolic capability of CO2 fixation, much attention has been focused on understanding the unique pathways associated with acetogens, particularly their metabolic coupling of CO2 fixation to energy conservation. Most known acetogens are phylogenetically and metabolically diverse bacteria present in 23 different bacterial genera. With the increased volume of available genome information, acetogenic bacterial genomes can be analyzed by comparative genome analysis. Even with the genetic diversity that exists among acetogens, the Wood-Ljungdahl pathway, a central metabolic pathway, and cofactor biosynthetic pathways are highly conserved for autotrophic growth. Additionally, comparative genome analysis revealed that most genes in the acetogen-specific core genome were associated with the Wood-Ljungdahl pathway. The conserved enzymes and those predicted as missing can provide insight into biological differences between acetogens and allow for the discovery of promising candidates for industrial applications.
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Affiliation(s)
- Jongoh Shin
- Systems and Synthetic Biology Laboratory, Department of Biological Sciences and KI for the BioCentury, Korea Advanced Institute of Science and Technology Daejeon, South Korea
| | - Yoseb Song
- Systems and Synthetic Biology Laboratory, Department of Biological Sciences and KI for the BioCentury, Korea Advanced Institute of Science and Technology Daejeon, South Korea
| | - Yujin Jeong
- Systems and Synthetic Biology Laboratory, Department of Biological Sciences and KI for the BioCentury, Korea Advanced Institute of Science and Technology Daejeon, South Korea
| | - Byung-Kwan Cho
- Systems and Synthetic Biology Laboratory, Department of Biological Sciences and KI for the BioCentury, Korea Advanced Institute of Science and TechnologyDaejeon, South Korea; Intelligent Synthetic Biology CenterDaejeon, South Korea
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