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Protasov E, Nonoh JO, Kästle Silva JM, Mies US, Hervé V, Dietrich C, Lang K, Mikulski L, Platt K, Poehlein A, Köhler-Ramm T, Miambi E, Boga HI, Feldewert C, Ngugi DK, Plarre R, Sillam-Dussès D, Šobotník J, Daniel R, Brune A. Diversity and taxonomic revision of methanogens and other archaea in the intestinal tract of terrestrial arthropods. Front Microbiol 2023; 14:1281628. [PMID: 38033561 PMCID: PMC10684969 DOI: 10.3389/fmicb.2023.1281628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Accepted: 10/13/2023] [Indexed: 12/02/2023] Open
Abstract
Methane emission by terrestrial invertebrates is restricted to millipedes, termites, cockroaches, and scarab beetles. The arthropod-associated archaea known to date belong to the orders Methanobacteriales, Methanomassiliicoccales, Methanomicrobiales, and Methanosarcinales, and in a few cases also to non-methanogenic Nitrososphaerales and Bathyarchaeales. However, all major host groups are severely undersampled, and the taxonomy of existing lineages is not well developed. Full-length 16S rRNA gene sequences and genomes of arthropod-associated archaea are scarce, reference databases lack resolution, and the names of many taxa are either not validly published or under-classified and require revision. Here, we investigated the diversity of archaea in a wide range of methane-emitting arthropods, combining phylogenomic analysis of isolates and metagenome-assembled genomes (MAGs) with amplicon sequencing of full-length 16S rRNA genes. Our results allowed us to describe numerous new species in hitherto undescribed taxa among the orders Methanobacteriales (Methanacia, Methanarmilla, Methanobaculum, Methanobinarius, Methanocatella, Methanoflexus, Methanorudis, and Methanovirga, all gen. nova), Methanomicrobiales (Methanofilum and Methanorbis, both gen. nova), Methanosarcinales (Methanofrustulum and Methanolapillus, both gen. nova), Methanomassiliicoccales (Methanomethylophilaceae fam. nov., Methanarcanum, Methanogranum, Methanomethylophilus, Methanomicula, Methanoplasma, Methanoprimaticola, all gen. nova), and the new family Bathycorpusculaceae (Bathycorpusculum gen. nov.). Reclassification of amplicon libraries from this and previous studies using this new taxonomic framework revealed that arthropods harbor only CO2 and methyl-reducing hydrogenotrophic methanogens. Numerous genus-level lineages appear to be present exclusively in arthropods, suggesting long evolutionary trajectories with their termite, cockroach, and millipede hosts, and a radiation into various microhabitats and ecological niches provided by their digestive tracts (e.g., hindgut compartments, gut wall, or anaerobic protists). The distribution patterns among the different host groups are often complex, indicating a mixed mode of transmission and a parallel evolution of invertebrate and vertebrate-associated lineages.
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Affiliation(s)
- Evgenii Protasov
- Research Group Insect Gut Microbiology and Symbiosis, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - James O. Nonoh
- Research Group Insect Gut Microbiology and Symbiosis, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Joana M. Kästle Silva
- Research Group Insect Gut Microbiology and Symbiosis, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Undine S. Mies
- Research Group Insect Gut Microbiology and Symbiosis, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Vincent Hervé
- Research Group Insect Gut Microbiology and Symbiosis, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Carsten Dietrich
- Research Group Insect Gut Microbiology and Symbiosis, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Kristina Lang
- Research Group Insect Gut Microbiology and Symbiosis, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Lena Mikulski
- Research Group Insect Gut Microbiology and Symbiosis, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Katja Platt
- Research Group Insect Gut Microbiology and Symbiosis, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Anja Poehlein
- Genomic and Applied Microbiology and Göttingen Genomics Laboratory, Institute of Microbiology and Genetics, Georg August University of Göttingen, Göttingen, Germany
| | - Tim Köhler-Ramm
- Research Group Insect Gut Microbiology and Symbiosis, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Edouard Miambi
- Evolutionary Ecology Department, Institute of Ecology and Environmental Sciences of Paris (iEES-Paris), University of Paris-Est Créteil (UPEC), Créteil, France
| | - Hamadi I. Boga
- Research Group Insect Gut Microbiology and Symbiosis, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Christopher Feldewert
- Research Group Insect Gut Microbiology and Symbiosis, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - David K. Ngugi
- Research Group Insect Gut Microbiology and Symbiosis, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Rudy Plarre
- Bundesanstalt für Materialforschung und -prüfung, Berlin, Germany
| | - David Sillam-Dussès
- Laboratory of Experimental and Comparative Ethology (LEEC), UR 4443, Université Sorbonne Paris Nord, Villetaneuse, France
| | - Jan Šobotník
- Faculty of Tropical AgriSciences, Czech University of Life Sciences, Prague, Czechia
| | - Rolf Daniel
- Genomic and Applied Microbiology and Göttingen Genomics Laboratory, Institute of Microbiology and Genetics, Georg August University of Göttingen, Göttingen, Germany
| | - Andreas Brune
- Research Group Insect Gut Microbiology and Symbiosis, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
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2
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Bueno de Mesquita CP, Wu D, Tringe SG. Methyl-Based Methanogenesis: an Ecological and Genomic Review. Microbiol Mol Biol Rev 2023; 87:e0002422. [PMID: 36692297 PMCID: PMC10029344 DOI: 10.1128/mmbr.00024-22] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Methyl-based methanogenesis is one of three broad categories of archaeal anaerobic methanogenesis, including both the methyl dismutation (methylotrophic) pathway and the methyl-reducing (also known as hydrogen-dependent methylotrophic) pathway. Methyl-based methanogenesis is increasingly recognized as an important source of methane in a variety of environments. Here, we provide an overview of methyl-based methanogenesis research, including the conditions under which methyl-based methanogenesis can be a dominant source of methane emissions, experimental methods for distinguishing different pathways of methane production, molecular details of the biochemical pathways involved, and the genes and organisms involved in these processes. We also identify the current gaps in knowledge and present a genomic and metagenomic survey of methyl-based methanogenesis genes, highlighting the diversity of methyl-based methanogens at multiple taxonomic levels and the widespread distribution of known methyl-based methanogenesis genes and families across different environments.
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Affiliation(s)
| | - Dongying Wu
- Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Susannah G. Tringe
- Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, California, USA
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
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Yu G, Chen J, Wang G, Chen H, Huang J, Li Y, Wang W, Song F, Ma Y, Wang Q, Wang M, Ling T, Shu Z, Sun J, Yu Z. Recent advances in constructed wetlands methane reduction: Mechanisms and methods. Front Microbiol 2023; 14:1106332. [PMID: 36819020 PMCID: PMC9936987 DOI: 10.3389/fmicb.2023.1106332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 01/10/2023] [Indexed: 02/05/2023] Open
Abstract
Constructed wetlands (CWs) are artificial systems that use natural processes to treat wastewater containing organic pollutants. This approach has been widely applied in both developing and developed countries worldwide, providing a cost-effective method for industrial wastewater treatment and the improvement of environmental water quality. However, due to the large organic carbon inputs, CWs is produced in varying amounts of CH4 and have the potential to become an important contributor to global climate change. Subsequently, research on the mitigation of CH4 emissions by CWs is key to achieving sustainable, low-carbon dependency wastewater treatment systems. This review evaluates the current research on CH4 emissions from CWs through bibliometric analysis, summarizing the reported mechanisms of CH4 generation, transfer and oxidation in CWs. Furthermore, the important environmental factors driving CH4 generation in CW systems are summarized, including: temperature, water table position, oxidation reduction potential, and the effects of CW characteristics such as wetland type, plant species composition, substrate type, CW-coupled microbial fuel cell, oxygen supply, available carbon source, and salinity. This review provides guidance and novel perspectives for sustainable and effective CW management, as well as for future studies on CH4 reduction in CWs.
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Affiliation(s)
- Guanlong Yu
- School of Hydraulic and Environmental Engineering, Changsha University of Science & Technology, Changsha, China,Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, Changsha University of Science and Technology, Changsha, China
| | - Jundan Chen
- School of Hydraulic and Environmental Engineering, Changsha University of Science & Technology, Changsha, China,Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, Changsha University of Science and Technology, Changsha, China
| | - Guoliang Wang
- School of Hydraulic and Environmental Engineering, Changsha University of Science & Technology, Changsha, China,Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, Changsha University of Science and Technology, Changsha, China
| | - Huifang Chen
- School of Hydraulic and Environmental Engineering, Changsha University of Science & Technology, Changsha, China,Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, Changsha University of Science and Technology, Changsha, China
| | - Jiajun Huang
- School of Hydraulic and Environmental Engineering, Changsha University of Science & Technology, Changsha, China,Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, Changsha University of Science and Technology, Changsha, China
| | - Yifu Li
- School of Hydraulic and Environmental Engineering, Changsha University of Science & Technology, Changsha, China,Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, Changsha University of Science and Technology, Changsha, China
| | - Wenming Wang
- Technology Center, Hunan Pilot Yanghu Reclaimed Water Co., Ltd., Changsha, China,*Correspondence: Wenming Wang,
| | - Fengming Song
- Technology Center, Hunan Pilot Yanghu Reclaimed Water Co., Ltd., Changsha, China
| | - Yuanjun Ma
- Technology Department, Hunan Rongantai Ecological Technology Co., Ltd., Changsha, China
| | - Qi Wang
- Technology and Information Department, CCCC-TDC Environmental Engineering Co., Ltd., Tianjin, China
| | - Miaomiao Wang
- Technology and Information Department, CCCC-TDC Environmental Engineering Co., Ltd., Tianjin, China
| | - Tao Ling
- Engineering Department, China Railway Wuju Group the First Engineering Co., Ltd., Changsha, China
| | - Zhilai Shu
- Engineering Department, China Railway Wuju Group the First Engineering Co., Ltd., Changsha, China
| | - Julong Sun
- School of Hydraulic and Environmental Engineering, Changsha University of Science & Technology, Changsha, China,Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, Changsha University of Science and Technology, Changsha, China
| | - Zhi Yu
- School of Hydraulic and Environmental Engineering, Changsha University of Science & Technology, Changsha, China,Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, Changsha University of Science and Technology, Changsha, China
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Supplementation of Sulfide or Acetate and 2-Mercaptoethane Sulfonate Restores Growth of the Methanosarcina acetivorans Δ hdrABC Deletion Mutant during Methylotrophic Methanogenesis. Microorganisms 2023; 11:microorganisms11020327. [PMID: 36838292 PMCID: PMC9963511 DOI: 10.3390/microorganisms11020327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 01/03/2023] [Accepted: 01/21/2023] [Indexed: 01/31/2023] Open
Abstract
Methanogenic archaea are important organisms in the global carbon cycle that grow by producing methane gas. Methanosarcina acetivorans is a methanogenic archaeum that can grow using methylated compounds, carbon monoxide, or acetate and produces renewable methane as a byproduct. However, there is limited knowledge of how combinations of substrates may affect metabolic fluxes in methanogens. Previous studies have shown that heterodisulfide reductase, the terminal oxidase in the electron transport system, is an essential enzyme in all methanogens. Deletion of genes encoding the nonessential methylotrophic heterodisulfide reductase enzyme (HdrABC) results in slower growth rate but increased metabolic efficiency. We hypothesized that increased sulfide, supplementation of mercaptoethanesulfonate (coenzyme M, CoM-SH), or acetate would metabolically alleviate the effect of the ΔhdrABC mutation. Increased sulfide improved growth of the mutant as expected; however, supplementation of both CoM-SH and acetate together were necessary to reduce the effect of the ΔhdrABC mutation. Supplementation of CoM-SH or acetate alone did not improve growth. These results support our model for the role of HdrABC in methanogenesis and suggest M.acetivorans is more efficient at conserving energy when supplemented with acetate. Our study suggests decreased Hdr enzyme activity can be overcome by nutritional supplementation with sulfide or coenzyme M and acetate, which are abundant in anaerobic environments.
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Lv Z, Ding J, Wang H, Wan J, Chen Y, Liang L, Yu T, Wang Y, Wang F. Isolation of a Novel Thermophilic Methanogen and the Evolutionary History of the Class Methanobacteria. BIOLOGY 2022; 11:biology11101514. [PMID: 36290418 PMCID: PMC9598358 DOI: 10.3390/biology11101514] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Revised: 10/13/2022] [Accepted: 10/14/2022] [Indexed: 11/16/2022]
Abstract
Methanogens can produce methane in anaerobic environments via the methanogenesis pathway, and are regarded as one of the most ancient life forms on Earth. They are ubiquitously distributed across distinct ecosystems and are considered to have a thermophilic origin. In this study, we isolated, pure cultured, and completely sequenced a single methanogen strain DL9LZB001, from a hot spring at Tengchong in Southwest China. DL9LZB001 is a thermophilic and hydrogenotrophic methanogen with an optimum growth temperature of 65 °C. It is a putative novel species, which has been named Methanothermobacter tengchongensis-a Class I methanogen belonging to the class Methanobacteria. Comparative genomic and ancestral analyses indicate that the class Methanobacteria originated in a hyperthermal environment and then evolved to adapt to ambient temperatures. This study extends the understanding of methanogens living in geothermal niches, as well as the origin and evolutionary history of these organisms in ecosystems with different temperatures.
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Affiliation(s)
- Zhenbo Lv
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Jiaxin Ding
- Instrumental Analysis Center, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Heng Wang
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Jiaxin Wan
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yifan Chen
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Lewen Liang
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Tiantian Yu
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yinzhao Wang
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
- Correspondence:
| | - Fengping Wang
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
- School of Oceanography, Shanghai Jiao Tong University, Shanghai 200240, China
- Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519000, China
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6
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Factors shaping the abundance and diversity of the gut archaeome across the animal kingdom. Nat Commun 2022; 13:3358. [PMID: 35688919 PMCID: PMC9187648 DOI: 10.1038/s41467-022-31038-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2021] [Accepted: 05/30/2022] [Indexed: 12/31/2022] Open
Abstract
Archaea are common constituents of the gut microbiome of humans, ruminants, and termites but little is known about their diversity and abundance in other animals. Here, we analyse sequencing and quantification data of archaeal and bacterial 16S rRNA genes from 250 species of animals covering a large taxonomic spectrum. We detect the presence of archaea in 175 animal species belonging to invertebrates, fish, amphibians, birds, reptiles and mammals. We identify five dominant gut lineages, corresponding to Methanobrevibacter, Methanosphaera, Methanocorpusculum, Methanimicrococcus and "Ca. Methanomethylophilaceae". Some archaeal clades, notably within Methanobrevibacter, are associated to certain hosts, suggesting specific adaptations. The non-methanogenic lineage Nitrososphaeraceae (Thaumarchaeota) is frequently present in animal samples, although at low abundance, but may have also adapted to the gut environment. Host phylogeny, diet type, fibre content, and intestinal tract physiology are major drivers of the diversity and abundance of the archaeome in mammals. The overall abundance of archaea is more influenced by these factors than that of bacteria. Methanogens reducing methyl-compounds with H2 can represent an important fraction of the overall methanogens in many animals. Together with CO2-reducing methanogens, they are influenced by diet and composition of gut bacteria. Our results provide key elements toward our understanding of the ecology of archaea in the gut, an emerging and important field of investigation.
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7
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Thomas CM, Taib N, Gribaldo S, Borrel G. Comparative genomic analysis of Methanimicrococcus blatticola provides insights into host adaptation in archaea and the evolution of methanogenesis. ISME COMMUNICATIONS 2021; 1:47. [PMID: 37938279 PMCID: PMC9723798 DOI: 10.1038/s43705-021-00050-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 07/08/2021] [Accepted: 08/26/2021] [Indexed: 05/15/2023]
Abstract
Other than the Methanobacteriales and Methanomassiliicoccales, the characteristics of archaea that inhabit the animal microbiome are largely unknown. Methanimicrococcus blatticola, a member of the Methanosarcinales, currently reunites two unique features within this order: it is a colonizer of the animal digestive tract and can only reduce methyl compounds with H2 for methanogenesis, a increasingly recognized metabolism in the archaea and whose origin remains debated. To understand the origin of these characteristics, we have carried out a large-scale comparative genomic analysis. We infer the loss of more than a thousand genes in M. blatticola, by far the largest genome reduction across all Methanosarcinales. These include numerous elements for sensing the environment and adapting to more stable gut conditions, as well as a significant remodeling of the cell surface components likely involved in host and gut microbiota interactions. Several of these modifications parallel those previously observed in phylogenetically distant archaea and bacteria from the animal microbiome, suggesting large-scale convergent mechanisms of adaptation to the gut. Strikingly, M. blatticola has lost almost all genes coding for the H4MPT methyl branch of the Wood-Ljungdahl pathway (to the exception of mer), a phenomenon never reported before in any member of Class I or Class II methanogens. The loss of this pathway illustrates one of the evolutionary processes that may have led to the emergence of methyl-reducing hydrogenotrophic methanogens, possibly linked to the colonization of organic-rich environments (including the animal gut) where both methyl compounds and hydrogen are abundant.
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Affiliation(s)
- Courtney M Thomas
- Department of Microbiology, UMR 2001, Unit Evolutionary Biology of the Microbial Cell, Institut Pasteur, Paris, France
- Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Najwa Taib
- Department of Microbiology, UMR 2001, Unit Evolutionary Biology of the Microbial Cell, Institut Pasteur, Paris, France
| | - Simonetta Gribaldo
- Department of Microbiology, UMR 2001, Unit Evolutionary Biology of the Microbial Cell, Institut Pasteur, Paris, France
| | - Guillaume Borrel
- Department of Microbiology, UMR 2001, Unit Evolutionary Biology of the Microbial Cell, Institut Pasteur, Paris, France.
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Feldewert C, Lang K, Brune A. The hydrogen threshold of obligately methyl-reducing methanogens. FEMS Microbiol Lett 2021; 367:5895324. [PMID: 32821944 PMCID: PMC7485788 DOI: 10.1093/femsle/fnaa137] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 08/13/2020] [Indexed: 12/11/2022] Open
Abstract
Methanogenesis is the final step in the anaerobic degradation of organic matter. The most important substrates of methanogens are hydrogen plus carbon dioxide and acetate, but also the use of methanol, methylated amines, and aromatic methoxy groups appears to be more widespread than originally thought. Except for most members of the family Methanosarcinaceae, all methylotrophic methanogens require external hydrogen as reductant and therefore compete with hydrogenotrophic methanogens for this common substrate. Since methanogenesis from carbon dioxide consumes four molecules of hydrogen per molecule of methane, whereas methanogenesis from methanol requires only one, methyl-reducing methanogens should have an energetic advantage over hydrogenotrophic methanogens at low hydrogen partial pressures. However, experimental data on their hydrogen threshold is scarce and suffers from relatively high detection limits. Here, we show that the methyl-reducing methanogens Methanosphaera stadtmanae (Methanobacteriales), Methanimicrococcus blatticola (Methanosarcinales), and Methanomassiliicoccus luminyensis (Methanomassiliicoccales) consume hydrogen to partial pressures < 0.1 Pa, which is almost one order of magnitude lower than the thresholds for M. stadtmanae and M. blatticola reported in the only previous study on this topic. We conclude that methylotrophic methanogens should outcompete hydrogenotrophic methanogens for hydrogen and that their activity is limited by the availability of methyl groups.
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Affiliation(s)
- Christopher Feldewert
- Research Group Insect Gut Microbiology and Symbiosis, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Kristina Lang
- Research Group Insect Gut Microbiology and Symbiosis, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Andreas Brune
- Research Group Insect Gut Microbiology and Symbiosis, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
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9
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Methanogenesis in the Digestive Tracts of the Tropical Millipedes Archispirostreptus gigas (Diplopoda, Spirostreptidae) and Epibolus pulchripes (Diplopoda, Pachybolidae). Appl Environ Microbiol 2021; 87:e0061421. [PMID: 34020937 DOI: 10.1128/aem.00614-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Methanogens represent the final decomposition step in anaerobic degradation of organic matter, occurring in the digestive tracts of various invertebrates. However, factors determining their community structure and activity in distinct gut sections are still debated. In this study, we focused on the tropical millipede species Archispirostreptus gigas (Diplopoda, Spirostreptidae) and Epibolus pulchripes (Diplopoda, Pachybolidae), which release considerable amounts of methane. We aimed to characterize relationships between physicochemical parameters, methane production rates, and methanogen community structure in the two major gut sections, midgut and hindgut. Microsensor measurements revealed that both sections were strictly anoxic, with reducing conditions prevailing in both millipedes. Hydrogen concentration peaked in the anterior hindgut of E. pulchripes. In both species, the intestinal pH was significantly higher in the hindgut than in the midgut. An accumulation of acetate and formate in the gut indicated bacterial fermentation activities in the digestive tracts of both species. Phylogenetic analysis of 16S rRNA genes showed a prevalence of Methanobrevibacter spp. (Methanobacteriales), accompanied by a small fraction of so-far-unclassified "Methanomethylophilaceae" (Methanomassiliicoccales), in both species, which suggests that methanogenesis is mostly hydrogenotrophic. We conclude that anoxic conditions, negative redox potential, and bacterial production of hydrogen and formate promote gut colonization by methanogens. The higher activities of methanogens in the hindgut are explained by the higher pH of this compartment and their association with ciliates, which are restricted to this compartment and present an additional source of methanogenic substrates. IMPORTANCE Methane (CH4) is the second most important atmospheric greenhouse gas after CO2 and is believed to account for 17% of global warming. Methanogens are a diverse group of archaea and can be found in various anoxic habitats, including digestive tracts of plant-feeding animals. Termites, cockroaches, the larvae of scarab beetles, and millipedes are the only arthropods known to host methanogens and emit large amounts of methane. Millipedes are ranked as the third most important detritivores after termites and earthworms, and they are considered keystone species in many terrestrial ecosystems. Both methane-producing and non-methane-emitting species of millipedes have been observed, but what limits their methanogenic potential is not known. In the present study, we show that physicochemical gut conditions and the distribution of symbiotic ciliates are important factors determining CH4 emission in millipedes. We also found close similarities to other methane-emitting arthropods, which might be associated with their similar plant-feeding habits.
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Li Z, Wang X, Alberdi A, Deng J, Zhong Z, Si H, Zheng C, Zhou H, Wang J, Yang Y, Wright ADG, Mao S, Zhang Z, Guan L, Li G. Comparative Microbiome Analysis Reveals the Ecological Relationships Between Rumen Methanogens, Acetogens, and Their Hosts. Front Microbiol 2020; 11:1311. [PMID: 32714292 PMCID: PMC7344211 DOI: 10.3389/fmicb.2020.01311] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2020] [Accepted: 05/25/2020] [Indexed: 01/08/2023] Open
Abstract
Ruminant methane, which is generated by methanogens through the consumption of hydrogen and supports the normal function of the rumen ecosystem, is a major source of greenhouse gases. Reductive acetogenesis by acetogens is a possible alternative sink that can dispose of hydrogen for acetate production. However, the distribution of rumen methanogens and acetogens along with the relationships among methanogens, acetogens, and their host are poorly understood. Therefore, we investigated the rumen methanogen and acetogen communities of 97 individual animals representing 14 ruminant species within three ruminant families Cervidae (deer), Bovidae (bovid), and Moschidae (musk deer). The results showed that the Methanobrevibacter spp. and acetogens associated with Eubacteriaceae were the most widespread methanogens and acetogens, respectively. However, other methanogens and acetogens exhibited host specificity in the rumen of reindeer and Chinese muntjac deer. Acetogen and methanogen communities were not correlated in these species, and the phylosymbiosis signature between host phylogeny and the composition of both communities was lacking. The abundance of Methanobrevibacter gottschalkii was negatively correlated with the degree of papillation of the rumen wall. Finally, co-occurrence analysis showed that the variation of the predicted methane yields was characterized by the interactive patterns between methanogens, acetogens, and concentrations of rumen metabolites. Our results show that rumen methanogen and acetogen communities have low compositional interdependence and do not exhibit parallel host evolution, which suggests that the strategies for mitigating methane production should be based on a species-specific rumen microbiota analysis.
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Affiliation(s)
- Zhipeng Li
- Department of Special Economic Animal Nutrition and Feed Science, Institute of Special Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, Changchun, China.,College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
| | - Xiaoxu Wang
- Department of Special Economic Animal Nutrition and Feed Science, Institute of Special Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, Changchun, China
| | - Antton Alberdi
- Center for Evolutionary Hologenomics, GLOBE Institute, University of Copenhagen, Copenhagen, Denmark
| | - Jiabo Deng
- Chengdu Zoological Garden, Chengdu, China
| | - Zhenyu Zhong
- Beijing Milu Ecological Research Center, Beijing, China
| | - Huazhe Si
- Department of Special Economic Animal Nutrition and Feed Science, Institute of Special Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, Changchun, China
| | - Chengli Zheng
- Sichuan Institute of Musk Deer Breeding, Chengdu, China
| | - Hanlin Zhou
- Tropical Crops Genetic Resources Institute, Chinese Academy of Tropical Agricultural Science, Danzhou, China
| | - Jianming Wang
- Sichuan Institute of Musk Deer Breeding, Chengdu, China
| | - Yifeng Yang
- Department of Special Economic Animal Nutrition and Feed Science, Institute of Special Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, Changchun, China
| | - André-Denis G Wright
- College of Agricultural, Human, and Natural Resource Sciences, Washington State University, Pullman, WA, United States
| | - Shengyong Mao
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
| | - Zhigang Zhang
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China.,State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming, China
| | - Leluo Guan
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada
| | - Guangyu Li
- Department of Special Economic Animal Nutrition and Feed Science, Institute of Special Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, Changchun, China
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11
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Martínez-Álvaro M, Auffret MD, Stewart RD, Dewhurst RJ, Duthie CA, Rooke JA, Wallace RJ, Shih B, Freeman TC, Watson M, Roehe R. Identification of Complex Rumen Microbiome Interaction Within Diverse Functional Niches as Mechanisms Affecting the Variation of Methane Emissions in Bovine. Front Microbiol 2020; 11:659. [PMID: 32362882 PMCID: PMC7181398 DOI: 10.3389/fmicb.2020.00659] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 03/23/2020] [Indexed: 11/13/2022] Open
Abstract
A network analysis including relative abundances of all ruminal microbial genera (archaea, bacteria, fungi, and protists) and their genes was performed to improve our understanding of how the interactions within the ruminal microbiome affects methane emissions (CH4). Metagenomics and CH4 data were available from 63 bovines of a two-breed rotational cross, offered two basal diets. Co-abundance network analysis revealed 10 clusters of functional niches. The most abundant hydrogenotrophic Methanobacteriales with key microbial genes involved in methanogenesis occupied a different functional niche (i.e., "methanogenesis" cluster) than methylotrophic Methanomassiliicoccales (Candidatus Methanomethylophylus) and acetogens (Blautia). Fungi and protists clustered together and other plant fiber degraders like Fibrobacter occupied a seperate cluster. A Partial Least Squares analysis approach to predict CH4 variation in each cluster showed the methanogenesis cluster had the best prediction ability (57.3%). However, the most important explanatory variables in this cluster were genes involved in complex carbohydrate degradation, metabolism of sugars and amino acids and Candidatus Azobacteroides carrying nitrogen fixation genes, but not methanogenic archaea and their genes. The cluster containing Fibrobacter, isolated from other microorganisms, was positively associated with CH4 and explained 49.8% of its variability, showing fermentative advantages compared to other bacteria and fungi in providing substrates (e.g., formate) for methanogenesis. In other clusters, genes with enhancing effect on CH4 were related to lactate and butyrate (Butyrivibrio and Pseudobutyrivibrio) production and simple amino acids metabolism. In comparison, ruminal genes negatively related to CH4 were involved in carbohydrate degradation via lactate and succinate and synthesis of more complex amino acids by γ-Proteobacteria. When analyzing low- and high-methane emitters data in separate networks, competition between methanogens in the methanogenesis cluster was uncovered by a broader diversity of methanogens involved in the three methanogenesis pathways and larger interactions within and between communities in low compared to high emitters. Generally, our results suggest that differences in CH4 are mainly explained by other microbial communities and their activities rather than being only methanogens-driven. Our study provides insight into the interactions of the rumen microbial communities and their genes by uncovering functional niches affecting CH4, which will benefit the development of efficient CH4 mitigation strategies.
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Affiliation(s)
- Marina Martínez-Álvaro
- Scotland’s Rural College, Edinburgh, United Kingdom
- Institute for Animal Science and Technology, Polytechnic University of Valencia, Valencia, Spain
| | | | - Robert D. Stewart
- Edinburgh Genomics, The Roslin Institute and R(D)SVS, The University of Edinburgh, Edinburgh, United Kingdom
| | | | | | | | - R. John Wallace
- The Rowett Institute, University of Aberdeen, Aberdeen, United Kingdom
| | - Barbara Shih
- Division of Genetics and Genomics, The Roslin Institute and R(D)SVS, The University of Edinburgh, Edinburgh, United Kingdom
| | - Tom C. Freeman
- Division of Genetics and Genomics, The Roslin Institute and R(D)SVS, The University of Edinburgh, Edinburgh, United Kingdom
| | - Mick Watson
- Edinburgh Genomics, The Roslin Institute and R(D)SVS, The University of Edinburgh, Edinburgh, United Kingdom
- Division of Genetics and Genomics, The Roslin Institute and R(D)SVS, The University of Edinburgh, Edinburgh, United Kingdom
| | - Rainer Roehe
- Scotland’s Rural College, Edinburgh, United Kingdom
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12
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Methylotrophic methanogens everywhere - physiology and ecology of novel players in global methane cycling. Biochem Soc Trans 2020; 47:1895-1907. [PMID: 31819955 DOI: 10.1042/bst20180565] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 11/20/2019] [Accepted: 11/21/2019] [Indexed: 01/14/2023]
Abstract
Research on methanogenic Archaea has experienced a revival, with many novel lineages of methanogens recently being found through cultivation and suggested via metagenomics approaches, respectively. Most of these lineages comprise Archaea (potentially) capable of methanogenesis from methylated compounds, a pathway that had previously received comparably little attention. In this review, we provide an overview of these new lineages with a focus on the Methanomassiliicoccales. These lack the Wood-Ljungdahl pathway and employ a hydrogen-dependent methylotrophic methanogenesis pathway fundamentally different from traditional methylotrophic methanogens. Several archaeal candidate lineages identified through metagenomics, such as the Ca. Verstraetearchaeota and Ca. Methanofastidiosa, encode genes for a methylotrophic methanogenesis pathway similar to the Methanomassiliicoccales. Thus, the latter are emerging as a model system for physiological, biochemical and ecological studies of hydrogen-dependent methylotrophic methanogens. Methanomassiliicoccales occur in a large variety of anoxic habitats including wetlands and animal intestinal tracts, i.e. in the major natural and anthropogenic sources of methane emissions, respectively. Especially in ruminant animals, they likely are among the major methane producers. Taken together, (hydrogen-dependent) methylotrophic methanogens are much more diverse and widespread than previously thought. Considering the role of methane as potent greenhouse gas, resolving the methanogenic nature of a broad range of putative novel methylotrophic methanogens and assessing their role in methane emitting environments are pressing issues for future research on methanogens.
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13
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Tegtmeier D, Belitz A, Radek R, Heimerl T, Brune A. Ereboglobus luteus gen. nov. sp. nov. from cockroach guts, and new insights into the oxygen relationship of the genera Opitutus and Didymococcus ( Verrucomicrobia : Opitutaceae ). Syst Appl Microbiol 2018; 41:101-112. [DOI: 10.1016/j.syapm.2017.10.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 10/19/2017] [Accepted: 10/28/2017] [Indexed: 11/25/2022]
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14
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Brune A. Methanogens in the Digestive Tract of Termites. (ENDO)SYMBIOTIC METHANOGENIC ARCHAEA 2018. [DOI: 10.1007/978-3-319-98836-8_6] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
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15
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Sorokin DY, Makarova KS, Abbas B, Ferrer M, Golyshin PN, Galinski EA, Ciordia S, Mena MC, Merkel AY, Wolf YI, van Loosdrecht MCM, Koonin EV. Discovery of extremely halophilic, methyl-reducing euryarchaea provides insights into the evolutionary origin of methanogenesis. Nat Microbiol 2017; 2:17081. [PMID: 28555626 PMCID: PMC5494993 DOI: 10.1038/nmicrobiol.2017.81] [Citation(s) in RCA: 132] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 04/18/2017] [Indexed: 01/24/2023]
Abstract
Methanogenic archaea are major players in the global carbon cycle and in the biotechnology of anaerobic digestion. The phylum Euryarchaeota includes diverse groups of methanogens that are interspersed with non-methanogenic lineages. So far, methanogens inhabiting hypersaline environments have been identified only within the order Methanosarcinales. We report the discovery of a deep phylogenetic lineage of extremophilic methanogens in hypersaline lakes and present analysis of two nearly complete genomes from this group. Within the phylum Euryarchaeota, these isolates form a separate, class-level lineage 'Methanonatronarchaeia' that is most closely related to the class Halobacteria. Similar to the Halobacteria, 'Methanonatronarchaeia' are extremely halophilic and do not accumulate organic osmoprotectants. The high intracellular concentration of potassium implies that 'Methanonatronarchaeia' employ the 'salt-in' osmoprotection strategy. These methanogens are heterotrophic methyl-reducers that use C1-methylated compounds as electron acceptors and formate or hydrogen as electron donors. The genomes contain an incomplete and apparently inactivated set of genes encoding the upper branch of methyl group oxidation to CO2 as well as membrane-bound heterodisulfide reductase and cytochromes. These features differentiate 'Methanonatronarchaeia' from all known methyl-reducing methanogens. The discovery of extremely halophilic, methyl-reducing methanogens related to haloarchaea provides insights into the origin of methanogenesis and shows that the strategies employed by methanogens to thrive in salt-saturating conditions are not limited to the classical methylotrophic pathway.
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Affiliation(s)
- Dimitry Y Sorokin
- Winogradsky Institute of Microbiology, Centre for Biotechnology, Russian Academy of Sciences, Moscow, Russia.,Department of Biotechnology, Delft University of Technology, Delft, The Netherlands
| | - Kira S Makarova
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland 20894, USA
| | - Ben Abbas
- Department of Biotechnology, Delft University of Technology, Delft, The Netherlands
| | | | - Peter N Golyshin
- School of Biological Sciences, Bangor University, Gwynedd LL57 2UW, UK
| | - Erwin A Galinski
- Institute of Microbiology and Biotechnology, Rheinische Friedrich-Wilhelms University, Bonn, Germany
| | - Sergio Ciordia
- Proteomics Facility, Centro Nacional de Biotecnología, CSIC, Madrid, Spain
| | - María Carmen Mena
- Proteomics Facility, Centro Nacional de Biotecnología, CSIC, Madrid, Spain
| | - Alexander Y Merkel
- Winogradsky Institute of Microbiology, Centre for Biotechnology, Russian Academy of Sciences, Moscow, Russia
| | - Yuri I Wolf
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland 20894, USA
| | | | - Eugene V Koonin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland 20894, USA
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16
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Neubeck A, Sjöberg S, Price A, Callac N, Schnürer A. Effect of Nickel Levels on Hydrogen Partial Pressure and Methane Production in Methanogens. PLoS One 2016; 11:e0168357. [PMID: 27992585 PMCID: PMC5161503 DOI: 10.1371/journal.pone.0168357] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Accepted: 11/30/2016] [Indexed: 11/21/2022] Open
Abstract
Hydrogen (H2) consumption and methane (CH4) production in pure cultures of three different methanogens were investigated during cultivation with 0, 0.2 and 4.21 μM added nickel (Ni). The results showed that the level of dissolved Ni in the anaerobic growth medium did not notably affect CH4 production in the cytochrome-free methanogenic species Methanobacterium bryantii and Methanoculleus bourgensis MAB1, but affected CH4 formation rate in the cytochrome-containing Methanosarcina barkeri grown on H2and CO2. Methanosarcina barkeri also had the highest amounts of Ni in its cells, indicating that more Ni is needed by cytochrome-containing than by cytochrome-free methanogenic species. The concentration of Ni affected threshold values of H2 partial pressure (pH2) for all three methanogen species studied, with M. bourgensis MAB1 reaching pH2 values as low as 0.1 Pa when Ni was available in amounts used in normal anaerobic growth medium. To our knowledge, this is the lowest pH2 threshold recorded to date in pure methanogen culture, which suggests that M.bourgensis MAB1 have a competitive advantage over other species through its ability to grow at low H2 concentrations. Our study has implications for research on the H2-driven deep subsurface biosphere and biogas reactor performance.
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Affiliation(s)
- Anna Neubeck
- Department of Geological Sciences, Stockholm University, Stockholm, Sweden
- * E-mail:
| | - Susanne Sjöberg
- Department of Geological Sciences, Stockholm University, Stockholm, Sweden
| | - Alex Price
- Department of Physical Sciences, The Open University, Milton Keynes, United Kingdom
| | - Nolwenn Callac
- Department of Geological Sciences, Stockholm University, Stockholm, Sweden
| | - Anna Schnürer
- Department of Microbiology, BioCenter, Swedish University of Agricultural Sciences, Uppsala, Sweden
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17
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The Core Gut Microbiome of the American Cockroach, Periplaneta americana, Is Stable and Resilient to Dietary Shifts. Appl Environ Microbiol 2016; 82:6603-6610. [PMID: 27590811 DOI: 10.1128/aem.01837-16] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 08/26/2016] [Indexed: 12/28/2022] Open
Abstract
The omnivorous cockroach Periplaneta americana hosts a diverse hindgut microbiota encompassing hundreds of microbial species. In this study, we used 16S rRNA gene sequencing to examine the effect of diet on the composition of the P. americana hindgut microbial community. Results show that the hindgut microbiota of P. americana exhibit a highly stable core microbial community with low variance in compositions between individuals and minimal community change in response to dietary shifts. This core hindgut microbiome is shared between laboratory-hosted and wild-caught individuals, although wild-caught specimens exhibited a higher diversity of low-abundance microbes that were lost following extended cultivation under laboratory conditions. This taxonomic stability strongly contrasts with observations of the gut microbiota of mammals, which have been shown to be highly responsive to dietary change. A comparison of P. americana hindgut samples with human fecal samples indicated that the cockroach hindgut community exhibited higher alpha diversity but a substantially lower beta diversity than the human gut microbiome. This suggests that cockroaches have evolved unique mechanisms for establishing and maintaining a diverse and stable core microbiome. IMPORTANCE The gut microbiome plays an important role in the overall health of its host. A healthy gut microbiota typically assists with defense against pathogens and the digestion and absorption of nutrients from food, while dysbiosis of the gut microbiota has been associated with reduced health. In this study, we examined the composition and stability of the gut microbiota from the omnivorous cockroach Periplaneta americana. We found that P. americana hosts a diverse core gut microbiome that remains stable after drastic long-term changes in diet. While other insects, notably ant and bee species, have evolved mechanisms for maintaining a stable association with specific gut microbiota, these insects typically host low-diversity gut microbiomes and consume specialized diets. In contrast, P. americana hosts a gut microbiota that is highly species rich and consumes a diverse solid diet, suggesting that cockroaches have evolved unique mechanisms for developing and maintaining a stable gut microbiota.
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18
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Schmidt O, Hink L, Horn MA, Drake HL. Peat: home to novel syntrophic species that feed acetate- and hydrogen-scavenging methanogens. ISME JOURNAL 2016; 10:1954-66. [PMID: 26771931 DOI: 10.1038/ismej.2015.256] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Revised: 11/25/2015] [Accepted: 12/07/2015] [Indexed: 11/09/2022]
Abstract
Syntrophic bacteria drive the anaerobic degradation of certain fermentation products (e.g., butyrate, ethanol, propionate) to intermediary substrates (e.g., H2, formate, acetate) that yield methane at the ecosystem level. However, little is known about the in situ activities and identities of these syntrophs in peatlands, ecosystems that produce significant quantities of methane. The consumption of butyrate, ethanol or propionate by anoxic peat slurries at 5 and 15 °C yielded methane and CO2 as the sole accumulating products, indicating that the intermediates H2, formate and acetate were scavenged effectively by syntrophic methanogenic consortia. 16S rRNA stable isotope probing identified novel species/strains of Pelobacter and Syntrophomonas that syntrophically oxidized ethanol and butyrate, respectively. Propionate was syntrophically oxidized by novel species of Syntrophobacter and Smithella, genera that use different propionate-oxidizing pathways. Taxa not known for a syntrophic metabolism may have been involved in the oxidation of butyrate (Telmatospirillum-related) and propionate (unclassified Bacteroidetes and unclassified Fibrobacteres). Gibbs free energies (ΔGs) for syntrophic oxidations of ethanol and butyrate were more favorable than ΔGs for syntrophic oxidation of propionate. As a result of the thermodynamic constraints, acetate transiently accumulated in ethanol and butyrate treatments but not in propionate treatments. Aceticlastic methanogens (Methanosarcina, Methanosaeta) appeared to outnumber hydrogenotrophic methanogens (Methanocella, Methanoregula), reinforcing the likely importance of aceticlastic methanogenesis to the overall production of methane. ΔGs for acetogenesis from H2 to CO2 approximated to -20 kJ mol(-1) when acetate concentrations were low, indicating that acetogens may have contributed to the flow of carbon and reductant towards methane.
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Affiliation(s)
- Oliver Schmidt
- Department of Ecological Microbiology, University of Bayreuth, Bayreuth, Germany
| | - Linda Hink
- Department of Ecological Microbiology, University of Bayreuth, Bayreuth, Germany
| | - Marcus A Horn
- Department of Ecological Microbiology, University of Bayreuth, Bayreuth, Germany
| | - Harold L Drake
- Department of Ecological Microbiology, University of Bayreuth, Bayreuth, Germany
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19
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Jasso-Chávez R, Santiago-Martínez MG, Lira-Silva E, Pineda E, Zepeda-Rodríguez A, Belmont-Díaz J, Encalada R, Saavedra E, Moreno-Sánchez R. Air-adapted Methanosarcina acetivorans shows high methane production and develops resistance against oxygen stress. PLoS One 2015; 10:e0117331. [PMID: 25706146 PMCID: PMC4338226 DOI: 10.1371/journal.pone.0117331] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Accepted: 12/22/2014] [Indexed: 12/27/2022] Open
Abstract
Methanosarcina acetivorans, considered a strict anaerobic archaeon, was cultured in the presence of 0.4–1% O2 (atmospheric) for at least 6 months to generate air-adapted cells; further, the biochemical mechanisms developed to deal with O2 were characterized. Methane production and protein content, as indicators of cell growth, did not change in air-adapted cells respect to cells cultured under anoxia (control cells). In contrast, growth and methane production significantly decreased in control cells exposed for the first time to O2. Production of reactive oxygen species was 50 times lower in air-adapted cells versus control cells, suggesting enhanced anti-oxidant mechanisms that attenuated the O2 toxicity. In this regard, (i) the transcripts and activities of superoxide dismutase, catalase and peroxidase significantly increased; and (ii) the thiol-molecules (cysteine + coenzyme M-SH + sulfide) and polyphosphate contents were respectively 2 and 5 times higher in air-adapted cells versus anaerobic-control cells. Long-term cultures (18 days) of air-adapted cells exposed to 2% O2 exhibited the ability to form biofilms. These data indicate that M. acetivorans develops multiple mechanisms to contend with O2 and the associated oxidative stress, as also suggested by genome analyses for some methanogens.
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Affiliation(s)
- Ricardo Jasso-Chávez
- Departamento de Bioquímica, Instituto Nacional de Cardiología Ignacio Chávez, Mexico City, Mexico
- * E-mail:
| | | | - Elizabeth Lira-Silva
- Departamento de Bioquímica, Instituto Nacional de Cardiología Ignacio Chávez, Mexico City, Mexico
| | - Erika Pineda
- Departamento de Bioquímica, Instituto Nacional de Cardiología Ignacio Chávez, Mexico City, Mexico
| | | | - Javier Belmont-Díaz
- Departamento de Bioquímica, Instituto Nacional de Cardiología Ignacio Chávez, Mexico City, Mexico
| | - Rusely Encalada
- Departamento de Bioquímica, Instituto Nacional de Cardiología Ignacio Chávez, Mexico City, Mexico
| | - Emma Saavedra
- Departamento de Bioquímica, Instituto Nacional de Cardiología Ignacio Chávez, Mexico City, Mexico
| | - Rafael Moreno-Sánchez
- Departamento de Bioquímica, Instituto Nacional de Cardiología Ignacio Chávez, Mexico City, Mexico
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20
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Lang K, Schuldes J, Klingl A, Poehlein A, Daniel R, Brune A. New mode of energy metabolism in the seventh order of methanogens as revealed by comparative genome analysis of “Candidatus methanoplasma termitum”. Appl Environ Microbiol 2015; 81:1338-52. [PMID: 25501486 PMCID: PMC4309702 DOI: 10.1128/aem.03389-14] [Citation(s) in RCA: 149] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Accepted: 12/08/2014] [Indexed: 11/20/2022] Open
Abstract
The recently discovered seventh order of methanogens, the Methanomassiliicoccales (previously referred to as “Methanoplasmatales”), so far consists exclusively of obligately hydrogen-dependent methylotrophs. We sequenced the complete genome of “Candidatus Methanoplasma termitum” from a highly enriched culture obtained from the intestinal tract of termites and compared it with the previously published genomes of three other strains from the human gut, including the first isolate of the order. Like all other strains, “Ca. Methanoplasma termitum” lacks the entire pathway for CO2 reduction to methyl coenzyme Mand produces methane by hydrogen-dependent reduction of methanol or methylamines, which is consistent with additional physiological data. However, the shared absence of cytochromes and an energy-converting hydrogenase for the reoxidation of the ferredoxin produced by the soluble heterodisulfide reductase indicates that Methanomassiliicoccales employ a new mode of energy metabolism, which differs from that proposed for the obligately methylotrophic Methanosphaera stadtmanae. Instead, all strains possess a novel complex that is related to the F420:methanophenazine oxidoreductase (Fpo) of Methanosarcinales butlacks an F420-oxidizing module, resembling the apparently ferredoxin-dependent Fpo-like homolog in Methanosaeta thermophila. Since all Methanomassiliicoccales also lack the subunit E of the membrane-bound heterodisulfide reductase (HdrDE), wepropose that the Fpo-like complex interacts directly with subunit D, forming an energy-converting ferredoxin: heterodisulfideoxidoreductase. The dual function of heterodisulfide in Methanomassiliicoccales, which serves both in electron bifurcation and as terminal acceptor in a membrane-associated redox process, may be a unique characteristic of the novel order.
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Affiliation(s)
- Kristina Lang
- Department of Biogeochemistry, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Jörg Schuldes
- Göttingen Genomics Laboratory, Institute for Microbiology and Genetics, Georg-August-Universität Göttingen, Göttingen, Germany
| | - Andreas Klingl
- LOEWE Center for Synthetic Microbiology, Philipps-Universität Marburg, Marburg, Germany
| | - Anja Poehlein
- Göttingen Genomics Laboratory, Institute for Microbiology and Genetics, Georg-August-Universität Göttingen, Göttingen, Germany
| | - Rolf Daniel
- Göttingen Genomics Laboratory, Institute for Microbiology and Genetics, Georg-August-Universität Göttingen, Göttingen, Germany
| | - Andreas Brune
- Department of Biogeochemistry, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
- LOEWE Center for Synthetic Microbiology, Philipps-Universität Marburg, Marburg, Germany
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21
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Saengkerdsub S, Ricke SC. Ecology and characteristics of methanogenic archaea in animals and humans. Crit Rev Microbiol 2013; 40:97-116. [PMID: 23425063 DOI: 10.3109/1040841x.2013.763220] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In this review, the molecular techniques used in animal-based-methanogen studies will be discussed along with how methanogens interact not only with other microorganisms but with their animal hosts as well. These methods not only indicate the diversity and levels of methanogens, but also provide insight on their ecological functions. Most molecular techniques have been based on either 16S rRNA genes or methyl-coenzyme M reductase, a ubiquitous enzyme in methanogens. The most predominant methanogens in animals belong to the genus Methanobrevibacter. Besides methanogens contributing to overall H2 balance, methanogens also have mutual interactions with other bacteria. In addition to shared metabolic synergism, the host animal retrieves additional energy from the diet when methanogens are co-colonized with other normal flora. By comparing genes in methanogens with other bacteria, possible gene transfer between methanogens and other bacteria in the same environments appears to occur. Finally, diets in conjunction with the genetics of methanogens and hosts may represent the biological framework that dictate the extent of methanogen prevalence in these ecosystems. In addition, host evolution including the immune system could serve as an additional selective pressure for methanogen colonization.
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Affiliation(s)
- Suwat Saengkerdsub
- Department of Food Science, Center for Food Safety, University of Arkansas , Fayetteville, AR , USA , and
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22
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Brune A. Methanogens in the Digestive Tract of Termites. (ENDO)SYMBIOTIC METHANOGENIC ARCHAEA 2010. [DOI: 10.1007/978-3-642-13615-3_6] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Liu Y, Whitman WB. Metabolic, phylogenetic, and ecological diversity of the methanogenic archaea. Ann N Y Acad Sci 2008; 1125:171-89. [PMID: 18378594 DOI: 10.1196/annals.1419.019] [Citation(s) in RCA: 610] [Impact Index Per Article: 38.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Although of limited metabolic diversity, methanogenic archaea or methanogens possess great phylogenetic and ecological diversity. Only three types of methanogenic pathways are known: CO(2)-reduction, methyl-group reduction, and the aceticlastic reaction. Cultured methanogens are grouped into five orders based upon their phylogeny and phenotypic properties. In addition, uncultured methanogens that may represent new orders are present in many environments. The ecology of methanogens highlights their complex interactions with other anaerobes and the physical and chemical factors controlling their function.
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Affiliation(s)
- Yuchen Liu
- Department of Microbiology, University of Georgia, 541 Biological Sciences Building, Athens, GA 30605, USA
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Tholen A, Pester M, Brune A. Simultaneous methanogenesis and oxygen reduction by Methanobrevibacter cuticularis at low oxygen fluxes. FEMS Microbiol Ecol 2007; 62:303-12. [DOI: 10.1111/j.1574-6941.2007.00390.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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