1
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Li S, Deng Q, Xiang S, Zhang Z, Zhou Y. Study on the changes and transformation characteristics of intermediate liquid products in hydrogen sulfide production from lignite degraded by sulfate-reducing bacteria. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2024; 46:408. [PMID: 39215874 DOI: 10.1007/s10653-024-02202-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2024] [Accepted: 08/27/2024] [Indexed: 09/04/2024]
Abstract
The changes and transformation laws of intermediate liquid-phase products during the anaerobic degradation of lignite by sulfate-reducing bacteria in the formation of hydrogen sulfide play an important role in supplementing and improving the existing theories on the genesis of hydrogen sulfide gas in coal mines. In this paper, H2S gas and key intermediate liquid-phase products produced during the anaerobic degradation of lignite by sulfate-reducing bacteria were detected and analyzed by gas chromatography and gas chromatography-mass spectrometry. The results showed that the process of hydrogen sulfide production from lignite degradation by sulfate-reducing bacteria can be roughly divided into four stages: slow production phase, rapid growth phase, steady production phase, and slight decline phase. In this reaction system, the SO42- concentration showed a decreasing trend, the pH value showed an increasing trend, and the ORP value decreased and then slightly increased with time. Ten volatile component types were detected during the experiment: straight-chain alkanes, branched-chain alkanes, alcohols, aldehydes, ketones, olefins, amines, lipids, acids and phenols. The key components in the intermediate liquid phase products were straight chain alkanes, straight chain alkanes, acids, alcohols, phenols and amines. PAHs, alkanes, and phenols are closely related to H2S production, while amides stimulate nitrogen production. The process is divided into three stages: hydrolysis stage, H2S gas production stage, and decay stage. Liquid-phase intermediates play an important role in the formation process of coal mine BSR hydrogen sulfide and the mechanism of coal mine H2S genesis.
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Affiliation(s)
- Shuai Li
- School of Safety Science and Engineering, Henan Polytechnic University, Jiaozuo, 454003, China
| | - Qigen Deng
- School of Safety Science and Engineering, Henan Polytechnic University, Jiaozuo, 454003, China.
- State Key Laboratory Cultivation Base for Gas Geology and Gas Control, Henan Polytechnic University, Jiaozuo, 454003, China.
- Collaborative Innovation Center of Coal Safety Production of Henan Province, Jiaozuo, 454003, China.
| | - Sisi Xiang
- School of Safety Science and Engineering, Henan Polytechnic University, Jiaozuo, 454003, China
| | - Zhecheng Zhang
- School of Safety Science and Engineering, Henan Polytechnic University, Jiaozuo, 454003, China
| | - Yinzi Zhou
- School of Safety Science and Engineering, Henan Polytechnic University, Jiaozuo, 454003, China
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2
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Bahrami Moghadam E, Nguyen N, Wang Y, Cirino PC. Directed Evolution of Protein-Based Sensors for Anaerobic Biological Activation of Methane. BIOSENSORS 2024; 14:325. [PMID: 39056601 PMCID: PMC11275114 DOI: 10.3390/bios14070325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2024] [Revised: 06/24/2024] [Accepted: 06/27/2024] [Indexed: 07/28/2024]
Abstract
Microbial alkane degradation pathways provide biological routes for converting these hydrocarbons into higher-value products. We recently reported the functional expression of a methyl-alkylsuccinate synthase (Mas) system in Escherichia coli, allowing for the heterologous anaerobic activation of short-chain alkanes. However, the enzymatic activation of methane via natural or engineered alkylsuccinate synthases has yet to be reported. To address this, we employed high-throughput screening to engineer the itaconate (IA)-responsive regulatory protein ItcR (WT-ItcR) from Yersinia pseudotuberculosis to instead respond to methylsuccinate (MS, the product of methane addition to fumarate), resulting in genetically encoded biosensors for MS. Here, we describe ItcR variants that, when regulating fluorescent protein expression in E. coli, show increased sensitivity, improved overall response, and enhanced specificity toward exogenously added MS relative to the wild-type repressor. Structural modeling and analysis of the ItcR ligand binding pocket provide insights into the altered molecular recognition. In addition to serving as biosensors for screening alkylsuccinate synthases capable of methane activation, MS-responsive ItcR variants also establish a framework for the directed evolution of other molecular reporters, targeting longer-chain alkylsuccinate products or other succinate derivatives.
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Affiliation(s)
| | | | | | - Patrick C. Cirino
- Department of Chemical and Biomolecular Engineering, University of Houston, Houston, TX 77204-4004, USA; (E.B.M.)
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3
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Wu M, Liu X, Engelberts JP, Tyson GW, McIlroy SJ, Guo J. Anaerobic oxidation of ammonium and short-chain gaseous alkanes coupled to nitrate reduction by a bacterial consortium. THE ISME JOURNAL 2024; 18:wrae063. [PMID: 38624180 PMCID: PMC11090206 DOI: 10.1093/ismejo/wrae063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 03/01/2024] [Accepted: 04/12/2024] [Indexed: 04/17/2024]
Abstract
The bacterial species "Candidatus Alkanivorans nitratireducens" was recently demonstrated to mediate nitrate-dependent anaerobic oxidation of short-chain gaseous alkanes (SCGAs). In previous bioreactor enrichment studies, the species appeared to reduce nitrate in two phases, switching from denitrification to dissimilatory nitrate reduction to ammonium (DNRA) in response to nitrite accumulation. The regulation of this switch or the nature of potential syntrophic partnerships with other microorganisms remains unclear. Here, we describe anaerobic multispecies cultures of bacteria that couple the oxidation of propane and butane to nitrate reduction and the oxidation of ammonium (anammox). Batch tests with 15N-isotope labelling and multi-omic analyses collectively supported a syntrophic partnership between "Ca. A. nitratireducens" and anammox bacteria, with the former species mediating nitrate-driven oxidation of SCGAs, supplying the latter with nitrite for the oxidation of ammonium. The elimination of nitrite accumulation by the anammox substantially increased SCGA and nitrate consumption rates, whereas it suppressed DNRA. Removing ammonium supply led to its eventual production, the accumulation of nitrite, and the upregulation of DNRA gene expression for the abundant "Ca. A. nitratireducens". Increasing the supply of SCGA had a similar effect in promoting DNRA. Our results suggest that "Ca. A. nitratireducens" switches to DNRA to alleviate oxidative stress caused by nitrite accumulation, giving further insight into adaptability and ecology of this microorganism. Our findings also have important implications for the understanding of the fate of nitrogen and SCGAs in anaerobic environments.
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Affiliation(s)
- Mengxiong Wu
- Australian Centre for Water and Environmental Biotechnology (ACWEB, formerly AWMC), The University of Queensland, St Lucia, QLD 4072, Australia
| | - Xiawei Liu
- Australian Centre for Water and Environmental Biotechnology (ACWEB, formerly AWMC), The University of Queensland, St Lucia, QLD 4072, Australia
| | - J Pamela Engelberts
- Centre for Microbiome Research, School of Biomedical Sciences, Queensland University of Technology (QUT), Translational Research Institute, Woolloongabba, QLD 4102, Australia
| | - Gene W Tyson
- Centre for Microbiome Research, School of Biomedical Sciences, Queensland University of Technology (QUT), Translational Research Institute, Woolloongabba, QLD 4102, Australia
| | - Simon J McIlroy
- Centre for Microbiome Research, School of Biomedical Sciences, Queensland University of Technology (QUT), Translational Research Institute, Woolloongabba, QLD 4102, Australia
| | - Jianhua Guo
- Australian Centre for Water and Environmental Biotechnology (ACWEB, formerly AWMC), The University of Queensland, St Lucia, QLD 4072, Australia
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4
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Fan SQ, Wen WR, Xie GJ, Lu Y, Liu BF, Xing DF, Ma J, Ren NQ. Deep insights into the population shift of n-DAMO and Anammox in granular sludge: From sidestream to mainstream. WATER RESEARCH 2023; 244:120448. [PMID: 37619305 DOI: 10.1016/j.watres.2023.120448] [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: 04/28/2023] [Revised: 07/14/2023] [Accepted: 08/03/2023] [Indexed: 08/26/2023]
Abstract
Granular sludge combined n-DAMO and Anammox (n-D/A) is an energy-efficient biotechnique for the simultaneous removal of nitrogen and dissolved methane from wastewater. However, the lack of knowledge so far about the metabolic interactions between n-DAMO and Anammox in response to operation condition in granular sludge restrains the development of this biotechnology. To address this gap, three independent membrane granular sludge reactors (MGSRs) were designed to carry out the granule-based n-D/A process under different conditions. We provided the first deep insights into the metabolic interactions between n-DAMO and Anammox in granular sludge via combined metagenomic and metatranscriptomic analyses. Our study unveiled a clear population shift of n-DAMO community from Candidatus Methanoperedens to Candidatus Methylomirabilis from sidestream to mainstream. Candidatus Methanoperedens with relative abundance of 25.2% played the major role in nitrate reduction and methane oxidation under sidestream condition, indicated by the high expression activities of mcrA and narG. Candidatus Methylomirabilis dominated the microbial community under mainstream condition with relative abundance of 32.1%, supported by the high expression activities of pmoA and hao. Furthermore, a transition of Anammox population from Candidatus Kuenenia to Candidatus Brocadia was also observed from sidestream to mainstream. Candidatus Kuenenia and Candidatus Brocadia jointly contributed to the primary anaerobic ammonium oxidation suggested by the high expression value of hdh and hzs. Candidatus Methylomirabilis was speculated to perform ammonium oxidation mediated by pMMO under mainstream condition. These findings might help to reveal the microbial interactions and ecological niches of n-DAMO and Anammox microorganisms, shedding light on the optimization and management of the granule-based n-D/A system.
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Affiliation(s)
- Sheng-Qiang Fan
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Wan-Ru Wen
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Guo-Jun Xie
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
| | - Yang Lu
- The Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, Queensland 4072, Australia
| | - Bing-Feng Liu
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - De-Feng Xing
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Jun Ma
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Nan-Qi Ren
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
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5
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Anaerobic oxidation of propane coupled to nitrate reduction by a lineage within the class Symbiobacteriia. Nat Commun 2022; 13:6115. [PMID: 36253480 PMCID: PMC9576796 DOI: 10.1038/s41467-022-33872-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 10/05/2022] [Indexed: 12/24/2022] Open
Abstract
Anaerobic microorganisms are thought to play a critical role in regulating the flux of short-chain gaseous alkanes (SCGAs; including ethane, propane and butane) from terrestrial and aquatic ecosystems to the atmosphere. Sulfate has been confirmed to act as electron acceptor supporting microbial anaerobic oxidation of SCGAs, yet several other energetically more favourable acceptors co-exist with these gases in anaerobic environments. Here, we show that a bioreactor seeded with biomass from a wastewater treatment facility can perform anaerobic propane oxidation coupled to nitrate reduction to dinitrogen gas and ammonium. The bioreactor was operated for more than 1000 days, and we used 13C- and 15N-labelling experiments, metagenomic, metatranscriptomic, metaproteomic and metabolite analyses to characterize the microbial community and the metabolic processes. The data collectively suggest that a species representing a novel order within the bacterial class Symbiobacteriia is responsible for the observed nitrate-dependent propane oxidation. The closed genome of this organism, which we designate as 'Candidatus Alkanivorans nitratireducens', encodes pathways for oxidation of propane to CO2 via fumarate addition, and for nitrate reduction, with all the key genes expressed during nitrate-dependent propane oxidation. Our results suggest that nitrate is a relevant electron sink for SCGA oxidation in anaerobic environments, constituting a new microbially-mediated link between the carbon and nitrogen cycles.
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6
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The pathway for coenzyme M biosynthesis in bacteria. Proc Natl Acad Sci U S A 2022; 119:e2207190119. [PMID: 36037354 PMCID: PMC9457059 DOI: 10.1073/pnas.2207190119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Mercaptoethane sulfonate or coenzyme M (CoM) is the smallest known organic cofactor and is most commonly associated with the methane-forming step in all methanogenic archaea but is also associated with the anaerobic oxidation of methane to CO2 in anaerobic methanotrophic archaea and the oxidation of short-chain alkanes in Syntrophoarchaeum species. It has also been found in a small number of bacteria capable of the metabolism of small organics. Although many of the steps for CoM biosynthesis in methanogenic archaea have been elucidated, a complete pathway for the biosynthesis of CoM in archaea or bacteria has not been reported. Here, we present the complete CoM biosynthesis pathway in bacteria, revealing distinct chemical steps relative to CoM biosynthesis in methanogenic archaea. The existence of different pathways represents a profound instance of convergent evolution. The five-step pathway involves the addition of sulfite, the elimination of phosphate, decarboxylation, thiolation, and the reduction to affect the sequential conversion of phosphoenolpyruvate to CoM. The salient features of the pathway demonstrate reactivities for members of large aspartase/fumarase and pyridoxal 5'-phosphate-dependent enzyme families.
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7
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Lemaire O, Wagner T. A Structural View of Alkyl-Coenzyme M Reductases, the First Step of Alkane Anaerobic Oxidation Catalyzed by Archaea. Biochemistry 2022; 61:805-821. [PMID: 35500274 PMCID: PMC9118554 DOI: 10.1021/acs.biochem.2c00135] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 04/14/2022] [Indexed: 11/28/2022]
Abstract
Microbial anaerobic oxidation of alkanes intrigues the scientific community by way of its impact on the global carbon cycle, and its biotechnological applications. Archaea are proposed to degrade short- and long-chain alkanes to CO2 by reversing methanogenesis, a theoretically reversible process. The pathway would start with alkane activation, an endergonic step catalyzed by methyl-coenzyme M reductase (MCR) homologues that would generate alkyl-thiols carried by coenzyme M. While the methane-generating MCR found in methanogens has been well characterized, the enzymatic activity of the putative alkane-fixing counterparts has not been validated so far. Such an absence of biochemical investigations contrasts with the current explosion of metagenomics data, which draws new potential alkane-oxidizing pathways in various archaeal phyla. Therefore, validating the physiological function of these putative alkane-fixing machines and investigating how their structures, catalytic mechanisms, and cofactors vary depending on the targeted alkane have become urgent needs. The first structural insights into the methane- and ethane-capturing MCRs highlighted unsuspected differences and proposed some explanations for their substrate specificity. This Perspective reviews the current physiological, biochemical, and structural knowledge of alkyl-CoM reductases and offers fresh ideas about the expected mechanistic and chemical differences among members of this broad family. We conclude with the challenges of the investigation of these particular enzymes, which might one day generate biofuels for our modern society.
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Affiliation(s)
- Olivier
N. Lemaire
- Max Planck Institute for
Marine Microbiology, Celsiusstraße 1, 28359 Bremen, Germany
| | - Tristan Wagner
- Max Planck Institute for
Marine Microbiology, Celsiusstraße 1, 28359 Bremen, Germany
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8
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Zhang C, Meckenstock RU, Weng S, Wei G, Hubert CRJ, Wang JH, Dong X. Marine sediments harbor diverse archaea and bacteria with the potential for anaerobic hydrocarbon degradation via fumarate addition. FEMS Microbiol Ecol 2021; 97:6171024. [PMID: 33720296 DOI: 10.1093/femsec/fiab045] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 03/12/2021] [Indexed: 11/13/2022] Open
Abstract
Marine sediments can contain large amounts of alkanes and methylated aromatic hydrocarbons that are introduced by natural processes or anthropogenic activities. These compounds can be biodegraded by anaerobic microorganisms via enzymatic addition of fumarate. However, the identity and ecological roles of a significant fraction of hydrocarbon degraders containing fumarate-adding enzymes (FAE) in various marine sediments remains unknown. By combining phylogenetic reconstructions, protein homolog modelling, and functional profiling of publicly available metagenomes and genomes, 61 draft bacterial and archaeal genomes encoding anaerobic hydrocarbon degradation via fumarate addition were obtained. Besides Desulfobacterota (previously known as Deltaproteobacteria) that are well-known to catalyze these reactions, Chloroflexi are dominant FAE-encoding bacteria in hydrocarbon-impacted sediments, potentially coupling sulfate reduction or fermentation to anaerobic hydrocarbon degradation. Among Archaea, besides Archaeoglobi previously shown to have this capability, genomes of Heimdallarchaeota, Lokiarchaeota, Thorarchaeota and Thermoplasmata also suggest fermentative hydrocarbon degradation using archaea-type FAE. These bacterial and archaeal hydrocarbon degraders occur in a wide range of marine sediments, including high abundances of FAE-encoding Asgard archaea associated with natural seeps and subseafloor ecosystems. Our results expand the knowledge of diverse archaeal and bacterial lineages engaged in anaerobic degradation of alkanes and methylated aromatic hydrocarbons.
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Affiliation(s)
- Chuwen Zhang
- School of Marine Sciences, Sun Yat-Sen University, 2 Daxue Road, Xiangzhou District, Zhuhai 519082, China
| | - Rainer U Meckenstock
- Environmental Microbiology and Biotechnology, University Duisburg-Essen, Universitätsstrasse 5, Essen 45141, Germany
| | - Shengze Weng
- School of Marine Sciences, Sun Yat-Sen University, 2 Daxue Road, Xiangzhou District, Zhuhai 519082, China
| | - Guangshan Wei
- School of Marine Sciences, Sun Yat-Sen University, 2 Daxue Road, Xiangzhou District, Zhuhai 519082, China.,Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, 184 Daxue Road, Siming District, Xiamen 361005, China
| | - Casey R J Hubert
- Department of Biological Sciences, University of Calgary, 2500 University Dr NW, Calgary, AB T2N1N4, Canada
| | - Jiang-Hai Wang
- School of Marine Sciences, Sun Yat-Sen University, 2 Daxue Road, Xiangzhou District, Zhuhai 519082, China
| | - Xiyang Dong
- School of Marine Sciences, Sun Yat-Sen University, 2 Daxue Road, Xiangzhou District, Zhuhai 519082, China.,Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), 2 Daxue Road, XiangZhou District, Zhuhai 519000, China
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9
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Thauer RK. Methyl (Alkyl)-Coenzyme M Reductases: Nickel F-430-Containing Enzymes Involved in Anaerobic Methane Formation and in Anaerobic Oxidation of Methane or of Short Chain Alkanes. Biochemistry 2019; 58:5198-5220. [PMID: 30951290 PMCID: PMC6941323 DOI: 10.1021/acs.biochem.9b00164] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
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Methyl-coenzyme
M reductase (MCR) catalyzes the methane-forming
step in methanogenic archaea. The active enzyme harbors the nickel(I)
hydrocorphin coenzyme F-430 as a prosthetic group and catalyzes the
reversible reduction of methyl-coenzyme M (CH3–S-CoM)
with coenzyme B (HS-CoM) to methane and CoM-S–S-CoB. MCR is
also involved in anaerobic methane oxidation in reverse of methanogenesis
and most probably in the anaerobic oxidation of ethane, propane, and
butane. The challenging question is how the unreactive CH3–S thioether bond in methyl-coenzyme M and the even more unreactive
C–H bond in methane and the other hydrocarbons are anaerobically
cleaved. A key to the answer is the negative redox potential (Eo′) of the Ni(II)F-430/Ni(I)F-430 couple
below −600 mV and the radical nature of Ni(I)F-430. However,
the negative one-electron redox potential is also the Achilles heel
of MCR; it makes the nickel enzyme one of the most O2-sensitive
enzymes known to date. Even under physiological conditions, the Ni(I)
in MCR is oxidized to the Ni(II) or Ni(III) states, e.g., when in
the cells the redox potential (E′) of the
CoM-S–S-CoB/HS-CoM and HS-CoB couple (Eo′ = −140 mV) gets too high. Methanogens therefore
harbor an enzyme system for the reactivation of inactivated MCR in
an ATP-dependent reduction reaction. Purification of active MCR in
the Ni(I) oxidation state is very challenging and has been achieved
in only a few laboratories. This perspective reviews the function,
structure, and properties of MCR, what is known and not known about
the catalytic mechanism, how the inactive enzyme is reactivated, and
what remains to be discovered.
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Affiliation(s)
- Rudolf K Thauer
- Max Planck Institute for Terrestrial Microbiology , Karl-von-Frisch-Strasse 10 , Marburg 35043 , Germany
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10
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Chen SC, Musat N, Lechtenfeld OJ, Paschke H, Schmidt M, Said N, Popp D, Calabrese F, Stryhanyuk H, Jaekel U, Zhu YG, Joye SB, Richnow HH, Widdel F, Musat F. Anaerobic oxidation of ethane by archaea from a marine hydrocarbon seep. Nature 2019; 568:108-111. [PMID: 30918404 DOI: 10.1038/s41586-019-1063-0] [Citation(s) in RCA: 91] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 02/27/2019] [Indexed: 11/09/2022]
Abstract
Ethane is the second most abundant component of natural gas in addition to methane, and-similar to methane-is chemically unreactive. The biological consumption of ethane under anoxic conditions was suggested by geochemical profiles at marine hydrocarbon seeps1-3, and through ethane-dependent sulfate reduction in slurries4-7. Nevertheless, the microorganisms and reactions that catalyse this process have to date remained unknown8. Here we describe ethane-oxidizing archaea that were obtained by specific enrichment over ten years, and analyse these archaea using phylogeny-based fluorescence analyses, proteogenomics and metabolite studies. The co-culture, which oxidized ethane completely while reducing sulfate to sulfide, was dominated by an archaeon that we name 'Candidatus Argoarchaeum ethanivorans'; other members were sulfate-reducing Deltaproteobacteria. The genome of Ca. Argoarchaeum contains all of the genes that are necessary for a functional methyl-coenzyme M reductase, and all subunits were detected in protein extracts. Accordingly, ethyl-coenzyme M (ethyl-CoM) was identified as an intermediate by liquid chromatography-tandem mass spectrometry. This indicated that Ca. Argoarchaeum initiates ethane oxidation by ethyl-CoM formation, analogous to the recently described butane activation by 'Candidatus Syntrophoarchaeum'9. Proteogenomics further suggests that oxidation of intermediary acetyl-CoA to CO2 occurs through the oxidative Wood-Ljungdahl pathway. The identification of an archaeon that uses ethane (C2H6) fills a gap in our knowledge of microorganisms that specifically oxidize members of the homologous alkane series (CnH2n+2) without oxygen. Detection of phylogenetic and functional gene markers related to those of Ca. Argoarchaeum at deep-sea gas seeps10-12 suggests that archaea that are able to oxidize ethane through ethyl-CoM are widespread members of the local communities fostered by venting gaseous alkanes around these seeps.
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Affiliation(s)
- Song-Can Chen
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany.,State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China
| | - Niculina Musat
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Oliver J Lechtenfeld
- Department of Analytical Chemistry, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Heidrun Paschke
- Department of Analytical Chemistry, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Matthias Schmidt
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Nedal Said
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Denny Popp
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Federica Calabrese
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Hryhoriy Stryhanyuk
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Ulrike Jaekel
- Max Planck Institute for Marine Microbiology, Bremen, Germany.,Department for Research Infrastructures, The Research Council of Norway, Oslo, Norway
| | - Yong-Guan Zhu
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China.,Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China
| | - Samantha B Joye
- Department of Marine Sciences, University of Georgia, Athens, GA, USA
| | - Hans-Hermann Richnow
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | | | - Florin Musat
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany. .,Max Planck Institute for Marine Microbiology, Bremen, Germany.
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