1
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Kim M, Cha IT, Li M, Park SJ. Unraveling interspecies cross-feeding during anaerobic lignin degradation for bioenergy applications. CHEMOSPHERE 2024; 361:142588. [PMID: 38866340 DOI: 10.1016/j.chemosphere.2024.142588] [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: 04/30/2024] [Revised: 06/04/2024] [Accepted: 06/10/2024] [Indexed: 06/14/2024]
Abstract
Lignin, a major component of plant biomass, remains underutilized for renewable biofuels due to its complex and heterogeneous structure. Although investigations into depolymerizing lignin using fungi are well-established, studies of microbial pathways that enable anaerobic lignin breakdown linked with methanogenesis are limited. Through an enrichment cultivation approach with inoculation of freshwater sediment, we enriched a microbial community capable of producing methane during anaerobic lignin degradation. We reconstructed the near-complete population genomes of key lignin degraders and methanogens using metagenome-assembled genomes finally selected in this study (MAGs; 92 bacterial and 4 archaeal MAGs affiliated into 45 and 2 taxonomic groups, respectively). This study provides genetic evidence of microbial interdependence in conversion of lignin to methane in a syntrophic community. Metagenomic analysis revealed metabolic linkages, with lignin-hydrolyzing and/or fermentative bacteria such as the genera Alkalibaculum and Propionispora transforming lignin breakdown products into compounds such as acetate to feed methanogens (two archaeal MAGs classified into the genus Methanosarcina or UBA6 of the family Methanomassiliicoccaceae). Understanding the synergistic relationships between microbes that convert lignin could inform strategies for producing renewable bioenergy and treating aromatic-contaminated environments through anaerobic biodegradation processes. Overall, this study offers fundamental insights into complex community-level anaerobic lignin metabolism, highlighting hitherto unknown players, interactions, and pathways in this biotechnologically valuable process.
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Affiliation(s)
- Minji Kim
- Department of Biology, Jeju National University, 102 Jejudaehak-ro, Jeju, 63243, South Korea
| | - In-Tae Cha
- Climate Change and Environmental Biology Research Division, National Institute of Biological Resources, Incheon, 22689, South Korea
| | - Meng Li
- Archaeal Biology Center, Institute for Advanced Study, Shenzhen University, Shenzhen, Guangdong, China; Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, Guangdong, China
| | - Soo-Je Park
- Department of Biology, Jeju National University, 102 Jejudaehak-ro, Jeju, 63243, South Korea.
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2
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Gaspari M, Ghiotto G, Centurion VB, Kotsopoulos T, Santinello D, Campanaro S, Treu L, Kougias PG. Decoding Microbial Responses to Ammonia Shock Loads in Biogas Reactors through Metagenomics and Metatranscriptomics. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:591-602. [PMID: 38112274 PMCID: PMC10785759 DOI: 10.1021/acs.est.3c07840] [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: 09/21/2023] [Revised: 11/17/2023] [Accepted: 11/28/2023] [Indexed: 12/21/2023]
Abstract
The presence of elevated ammonia levels is widely recognized as a significant contributor to process inhibition in biogas production, posing a common challenge for biogas plant operators. The present study employed a combination of biochemical, genome-centric metagenomic and metatranscriptomic data to investigate the response of the biogas microbiome to two shock loads induced by single pulses of elevated ammonia concentrations (i.e., 1.5 g NH4+/LR and 5 g NH4+/LR). The analysis revealed a microbial community of high complexity consisting of 364 Metagenome Assembled Genomes (MAGs). The hydrogenotrophic pathway was the primary route for methane production during the entire experiment, confirming its efficiency even at high ammonia concentrations. Additionally, metatranscriptomic analysis uncovered a metabolic shift in the methanogens Methanothrix sp. MA6 and Methanosarcina flavescens MX5, which switched their metabolism from the acetoclastic to the CO2 reduction route during the second shock. Furthermore, multiple genes associated with mechanisms for maintaining osmotic balance in the cell were upregulated, emphasizing the critical role of osmoprotection in the rapid response to the presence of ammonia. Finally, this study offers insights into the transcriptional response of an anaerobic digestion community, specifically focusing on the mechanisms involved in recovering from ammonia-induced stress.
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Affiliation(s)
- Maria Gaspari
- Soil
and Water Resources Institute, Hellenic Agricultural Organisation
Dimitra, Thermi, Thessaloniki 57001, Greece
- Department
of Hydraulics, Soil Science and Agricultural Engineering, School of
Agriculture, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece
| | - Gabriele Ghiotto
- Department
of Biology, University of Padova, Padova 35121, Italy
| | | | - Thomas Kotsopoulos
- Department
of Hydraulics, Soil Science and Agricultural Engineering, School of
Agriculture, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece
| | | | | | - Laura Treu
- Department
of Biology, University of Padova, Padova 35121, Italy
| | - Panagiotis G. Kougias
- Soil
and Water Resources Institute, Hellenic Agricultural Organisation
Dimitra, Thermi, Thessaloniki 57001, Greece
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3
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Euler S, Jeffrey LC, Maher DT, Johnston SG, Sugimoto R, Tait DR. Microbiome mediating methane and nitrogen transformations in a subterranean estuary. Environ Microbiol 2024; 26:e16558. [PMID: 38115223 DOI: 10.1111/1462-2920.16558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 12/05/2023] [Indexed: 12/21/2023]
Abstract
Subterranean estuaries (STEs) are important coastal biogeochemical reactors facilitating unique niches for microbial communities. A common approach in determining STE greenhouse gas and nutrient fluxes is to use terrestrial endmembers, not accounting for microbially mediated transformations throughout the STE. As such, the microbial ecology and spatial distribution of specialists that cycle compounds in STEs remain largely underexplored. In this study, we applied 16S rRNA amplicon sequencing with paired biogeochemical characterisations to spatially evaluate microbial communities transforming greenhouse gases and nutrients in an STE. We show that methanogens are most prevalent at the terrestrial end (up to 2.81% relative abundance) concomitant to the highest porewater methane, carbon dioxide and dissolved organic carbon concentrations (0.41 ± 0.02 μM, 273.31 ± 6.05 μM and 0.51 ± 0.02 mM, respectively). Lower ammonium concentrations corresponded with abundant nitrifying and ammonia-oxidising prokaryotes in the mixing zone (up to 11.65% relative abundance). Methane, ammonium and dissolved organic carbon concentrations all decreased by >50% from the terrestrial to the oceanic end of the 15 m transect. This study highlights the STE's hidden microbiome zonation, as well as the importance of accounting for microbial transformations mitigating nutrient and greenhouse gas fluxes to the coastal ecosystems.
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Affiliation(s)
- Sebastian Euler
- Faculty of Science and Engineering, Southern Cross University, Lismore, Australia
| | - Luke C Jeffrey
- Faculty of Science and Engineering, Southern Cross University, Lismore, Australia
| | - Damien T Maher
- Faculty of Science and Engineering, Southern Cross University, Lismore, Australia
| | - Scott G Johnston
- Faculty of Science and Engineering, Southern Cross University, Lismore, Australia
| | - Ryo Sugimoto
- Faculty of Marine Science and Technology, Fukui Prefectural University, Fukui, Japan
| | - Douglas R Tait
- Faculty of Science and Engineering, Southern Cross University, Lismore, Australia
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4
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Ahmad A, Ghufran R. Microbial granules on reactors performance during organic butyrate digestion: clean production. Crit Rev Biotechnol 2023; 43:1236-1256. [PMID: 36130802 DOI: 10.1080/07388551.2022.2103641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Accepted: 06/09/2022] [Indexed: 11/03/2022]
Abstract
This critical review for anaerobic degradation of complex organic compounds like butyrate using reactors has been enormously applied for biogas production. Biogas production rate has a great impact on: reactor granulation methanogenesis, nutrient content, shear velocity, organic loading and loss of nutrients taking place in the reactor continuously. Various technologies have been applied to closed anaerobic reactors to improve biogas production and treatment efficiency. Recent reviews showed that the application of closed anaerobic reactors can accelerate the degradation of organics like volatile fatty acid-butyrate and affect microbial biofilm formation by increasing the number of methanogens and increase methane production 16.5 L-1 CH4 L-1 POME-1. The closed anaerobic reactors with stable microbial biofilm and established organic load were responsible for the improvement of the reactor and methane production. The technology mentioned in this review can be used to monitor biogas concentration, which directly correlates to organic concentrations. This review attempts to evaluate interactions among the: degradation of organics, closed anaerobic reactors system, and microbial granules. This article provides a useful picture for the improvement of the degradation of organic butyrate for COD removal, biogas and methane production in an anaerobic closed reactor.
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Affiliation(s)
- Anwar Ahmad
- Civil and Environmental Engineering Department, College of Engineering and Architecture, University of Nizwa, Nizwa, Sultanate of Oman
| | - Roomana Ghufran
- Faculty of Civil Engineering and Earth Resources, University Malaysia Pahang (UMP) Lebuhraya Tun Razak, Gambang, Malaysia
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5
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Szuhaj M, Kakuk B, Wirth R, Rákhely G, Kovács KL, Bagi Z. Regulation of the methanogenesis pathways by hydrogen at transcriptomic level in time. Appl Microbiol Biotechnol 2023; 107:6315-6324. [PMID: 37610465 PMCID: PMC10560149 DOI: 10.1007/s00253-023-12700-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 06/22/2023] [Accepted: 07/14/2023] [Indexed: 08/24/2023]
Abstract
The biomethane formation from 4 H2 + CO2 by pure cultures of two methanogens, Methanocaldococcus fervens and Methanobacterium thermophilum, has been studied. The goal of the study was to understand the regulation of the enzymatic steps associated with biomethane biosynthesis by H2, using metagenomic, pan-genomic, and transcriptomic approaches. Methanogenesis in the autotrophic methanogen M. fervens could be easily "switched off" and "switched on" by H2/CO2 within about an hour. In contrast, the heterotrophic methanogen M. thermophilum was practically insensitive to the addition of the H2/CO2 trigger although this methanogen also converted H2/CO2 to CH4. From practical points of view, the regulatory function of H2/CO2 suggests that in the power-to-gas (P2G) renewable excess electricity conversion and storage systems, the composition of the biomethane-generating methanogenic community is essential for sustainable operation. In addition to managing the specific hydrogenotrophic methanogenesis biochemistry, H2/CO2 affected several, apparently unrelated, metabolic pathways. The redox-regulated overall biochemistry and symbiotic relationships in the methanogenic communities should be explored in order to make the P2G technology more efficient. KEY POINTS : • Hydrogenotrophic methanogens may respond distinctly to H2/CO2 in bio-CH4 formation. • H2/CO2 can also activate metabolic routes, which are apparently unrelated to methanogenesis. • Sustainable conversion of the fluctuating renewable electricity to bio-CH4 is an option.
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Affiliation(s)
- Márk Szuhaj
- Department of Biotechnology, University of Szeged, Szeged, Hungary
| | - Balázs Kakuk
- Department of Biotechnology, University of Szeged, Szeged, Hungary
- Department of Medical Biology, University of Szeged, Szeged, Hungary
| | - Roland Wirth
- Department of Biotechnology, University of Szeged, Szeged, Hungary
- Biological Research Center, Institute of Plant Biology, Szeged, Hungary
| | - Gábor Rákhely
- Department of Biotechnology, University of Szeged, Szeged, Hungary
- Biological Research Center, Institute of Biophysics, Szeged, Hungary
| | - Kornél Lajos Kovács
- Department of Biotechnology, University of Szeged, Szeged, Hungary
- Biological Research Center, Institute of Plant Biology, Szeged, Hungary
- Biological Research Center, Institute of Biophysics, Szeged, Hungary
| | - Zoltán Bagi
- Department of Biotechnology, University of Szeged, Szeged, Hungary.
- Biological Research Center, Institute of Plant Biology, Szeged, Hungary.
- Biological Research Center, Institute of Biophysics, Szeged, Hungary.
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6
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Volmer JG, McRae H, Morrison M. The evolving role of methanogenic archaea in mammalian microbiomes. Front Microbiol 2023; 14:1268451. [PMID: 37727289 PMCID: PMC10506414 DOI: 10.3389/fmicb.2023.1268451] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 08/18/2023] [Indexed: 09/21/2023] Open
Abstract
Methanogenic archaea (methanogens) represent a diverse group of microorganisms that inhabit various environmental and host-associated microbiomes. These organisms play an essential role in global carbon cycling given their ability to produce methane, a potent greenhouse gas, as a by-product of their energy production. Recent advances in culture-independent and -dependent studies have highlighted an increased prevalence of methanogens in the host-associated microbiome of diverse animal species. Moreover, there is increasing evidence that methanogens, and/or the methane they produce, may play a substantial role in human health and disease. This review addresses the expanding host-range and the emerging view of host-specific adaptations in methanogen biology and ecology, and the implications for host health and disease.
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Affiliation(s)
- James G. Volmer
- Centre for Microbiome Research, School of Biomedical Sciences, Queensland University of Technology (QUT), Translational Research Institute, Woolloongabba, QLD, Australia
| | - Harley McRae
- Faculty of Medicine, University of Queensland Frazer Institute, Translational Research Institute, Woolloongabba, QLD, Australia
| | - Mark Morrison
- Faculty of Medicine, University of Queensland Frazer Institute, Translational Research Institute, Woolloongabba, QLD, Australia
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7
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Kimisto A, Muia AW, Ong'ondo GO, Ndung'u K. Molecular characterization of microorganisms with industrial potential for methane production in sludge from Kangemi sewage treatment plant, Nyeri county-Kenya. Heliyon 2023; 9:e15715. [PMID: 37234610 PMCID: PMC10205513 DOI: 10.1016/j.heliyon.2023.e15715] [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] [Received: 10/05/2022] [Revised: 04/18/2023] [Accepted: 04/20/2023] [Indexed: 05/28/2023] Open
Abstract
Microbial consortia under anaerobic conditions are involved in oxidizing organic matter in the sludge to produce methane gas. However, in developing countries like Kenya, these microbes have not been fully identified to target them for the efficient harnessing of biofuel. This study collected wet sludge from two anaerobic digestion lagoons 1 and 2 that were operational during sampling at Kangemi Sewage Treatment Plant, in Nyeri County, Kenya. DNA was extracted from samples using commercially available ZymoBIOMICS™ DNA Miniprep Kit and sequenced using Shotgun metagenomics. Samples were analyzed using MG-RAST software (Project ID: mgp100988), which allowed for identifying microorganisms directly involved in various stages of methanogenesis pathways. The study found hydrogenotrophic methanogens, such as Methanospirillum (32%), Methanobacterium (27%), Methanobrevibacter (27%), and Methanosarcina (32%), being predominant in the lagoon communities, whereas acetoclastic microorganisms such as the Methanoregula (22%) and the acetate oxidazing bacteria such as Clostridia (68%) were the key microbes for that pathway in the sewage digester sludge. Furthermore, Methanothermobacter (18%), Methanosarcina (21%), Methanosaeta (15%), and Methanospirillum (13%) carried out the methylotrophic pathway. In contrast, Methanosarcina (23%),Methanoregula (14%), methanosaeta (13%), and methnanoprevibacter (13%) seemed to play an important role in the final step of methane release. This study concluded that the sludge produced from the Nyeri-Kangemi WWTP harbors microbes with significant potential for biogas production. The study recommends a pilot study to investigate the efficiency of the identified microbes for biogas production.
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Affiliation(s)
- Allan.K. Kimisto
- Department of Biological Sciences, Egerton University, P.O Box 536- 20115 Egerton, Kenya
| | - Anastasia W. Muia
- Department of Biological Sciences, Egerton University, P.O Box 536- 20115 Egerton, Kenya
| | - Geoffrey O. Ong'ondo
- Department of Biological Sciences, Egerton University, P.O Box 536- 20115 Egerton, Kenya
| | - Kimani.C. Ndung'u
- Kenya Agricultural and Livestock Research Organisation (KALRO), Njoro Station, Private Bag 20107 Njoro, Kenya
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8
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Volmer JG, Soo RM, Evans PN, Hoedt EC, Astorga Alsina AL, Woodcroft BJ, Tyson GW, Hugenholtz P, Morrison M. Isolation and characterisation of novel Methanocorpusculum species indicates the genus is ancestrally host-associated. BMC Biol 2023; 21:59. [PMID: 36949471 PMCID: PMC10035134 DOI: 10.1186/s12915-023-01524-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 01/20/2023] [Indexed: 03/24/2023] Open
Abstract
BACKGROUND With an increasing interest in the manipulation of methane produced from livestock cultivation, the microbiome of Australian marsupials provides a unique ecological and evolutionary comparison with 'low-methane' emitters. Previously, marsupial species were shown to be enriched for novel lineages of Methanocorpusculum, as well as Methanobrevibacter, Methanosphaera, and Methanomassiliicoccales. Despite sporadic reports of Methanocorpusculum from stool samples of various animal species, there remains little information on the impacts of these methanogens on their hosts. RESULTS Here, we characterise novel host-associated species of Methanocorpusculum, to explore unique host-specific genetic factors and their associated metabolic potential. We performed comparative analyses on 176 Methanocorpusculum genomes comprising 130 metagenome-assembled genomes (MAGs) recovered from 20 public animal metagenome datasets and 35 other publicly available Methanocorpusculum MAGs and isolate genomes of host-associated and environmental origin. Nine MAGs were also produced from faecal metagenomes of the common wombat (Vombatus ursinus) and mahogany glider (Petaurus gracilis), along with the cultivation of one axenic isolate from each respective animal; M. vombati (sp. nov.) and M. petauri (sp. nov.). CONCLUSIONS Through our analyses, we substantially expand the available genetic information for this genus by describing the phenotypic and genetic characteristics of 23 host-associated species of Methanocorpusculum. These lineages display differential enrichment of genes associated with methanogenesis, amino acid biosynthesis, transport system proteins, phosphonate metabolism, and carbohydrate-active enzymes. These results provide insights into the differential genetic and functional adaptations of these novel host-associated species of Methanocorpusculum and suggest that this genus is ancestrally host-associated.
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Affiliation(s)
- James G Volmer
- Faculty of Medicine, University of Queensland Frazer Institute, Translational Research Institute, Woolloongabba, 4102, Australia
- Centre for Microbiome Research, School of Biomedical Sciences, Queensland University of Technology (QUT), Translational Research Institute, Woolloongabba, 4102, Australia
| | - Rochelle M Soo
- School of Chemistry and Molecular Biosciences and Australian Centre for Ecogenomics, University of Queensland, Saint Lucia, 4072, Australia
| | - Paul N Evans
- School of Chemistry and Molecular Biosciences and Australian Centre for Ecogenomics, University of Queensland, Saint Lucia, 4072, Australia
| | - Emily C Hoedt
- Faculty of Medicine, University of Queensland Frazer Institute, Translational Research Institute, Woolloongabba, 4102, Australia
- Current Address: NHMRC Centre of Research Excellence (CRE) in Digestive Health, Hunter Medical Research Institute (HMRI), Newcastle, NSW, Australia
| | - Ana L Astorga Alsina
- Faculty of Medicine, University of Queensland Frazer Institute, Translational Research Institute, Woolloongabba, 4102, Australia
| | - Benjamin J Woodcroft
- Centre for Microbiome Research, School of Biomedical Sciences, Queensland University of Technology (QUT), Translational Research Institute, Woolloongabba, 4102, Australia
| | - Gene W Tyson
- Centre for Microbiome Research, School of Biomedical Sciences, Queensland University of Technology (QUT), Translational Research Institute, Woolloongabba, 4102, Australia
| | - Philip Hugenholtz
- School of Chemistry and Molecular Biosciences and Australian Centre for Ecogenomics, University of Queensland, Saint Lucia, 4072, Australia
| | - Mark Morrison
- Faculty of Medicine, University of Queensland Frazer Institute, Translational Research Institute, Woolloongabba, 4102, Australia.
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9
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Cao Q, Zhang W, Lian T, Wang S, Yin F, Zhou T, Wei X, Dong H. Revealing mechanism of micro-aeration for enhancing volatile fatty acids production from swine manure. BIORESOURCE TECHNOLOGY 2022; 365:128140. [PMID: 36252761 DOI: 10.1016/j.biortech.2022.128140] [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: 08/06/2022] [Revised: 10/10/2022] [Accepted: 10/11/2022] [Indexed: 06/16/2023]
Abstract
Micro-aeration is considered a new strategy for improving volatile fatty acids (VFAs) production of agricultural waste. This study investigated the effect and mechanism of micro-aeration of air and oxygen (O2) on VFAs production from swine manure. The results showed that Air-micro-aeration had the most significant improvement effect, with the highest VFAs of 8.21 g/L, which was increased by 22.4%. Moreover, the mixing effects of different micro-aeration were limited, and the microbial communities significantly varied. Firmicutes and Bacteroidota were the dominant hydrolytic and acidogenic bacteria, and Air-micro-aeration preferentially promoted electron transfer activity and energy generation. Methanosarcina, Methanocorpusculum, and Methanobrevibacter can adapt to environmental changes according to their different oxygen tolerance, and the consumption and conversion of VFAs by methanogens were slow under Air-micro-aeration condition. This study revealed mechanism of micro-aeration for improving VFAs production from swine manure, providing a theoretical basis for micro-aeration regulation optimization.
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Affiliation(s)
- Qitao Cao
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China
| | - Wanqin Zhang
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China
| | - Tianjing Lian
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China; College of Natural Resources and Environment, Northwest A&F University, Yangling 712100, PR China
| | - Shunli Wang
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China
| | - Fubin Yin
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China
| | - Tanlong Zhou
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China
| | - Xiaoman Wei
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China
| | - Hongmin Dong
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China.
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10
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Wang C, Wang Y, Wang Y, Liu L, Wang D, Ju F, Xia Y, Zhang T. Impacts of food waste to sludge ratios on microbial dynamics and functional traits in thermophilic digesters. WATER RESEARCH 2022; 219:118590. [PMID: 35597218 DOI: 10.1016/j.watres.2022.118590] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 04/18/2022] [Accepted: 05/10/2022] [Indexed: 06/15/2023]
Abstract
A self-stabilizing microbial community lays the foundation of the efficient biochemical reactions of the anaerobic digestion (AD) process. Despite extensive profiling of microbial community dynamics under varying operating parameters, the effects of food waste (FW) to feeding sewage sludge (FSS) ratios on the microbial assembly, functional traits, and syntrophic interspecies interactions in thermophilic microbial consortia remain poorly understood. Here, we investigated the long-term impacts of the FW: FSS ratio on the thermophilic AD microbiome using genome-centric metagenomics. Both the short reads (SRs) assembly, and the iterative hybrid assembly (IHA) of SRs and nanopore long reads (LRs) were used to reconstruct metagenome-assembled genomes (MAGs) and four microbial clusters were identified, demonstrating different microbial dynamics patterns in response to varying FW:FSS ratios. Cluster C1-C3 were comprised of full functional members with genetic potentials in fulfilling empirical AD biochemical reactions, wherein, syntrophic decarboxylating acetogens could interact with methanogens, and some microbes could be energized by the electron bifurcation mechanism to drive thermodynamics unfavorable reactions. We found the co-existence of both acetogenic and hydrogenotrophic methanogens in the AD microbiome, and they altered their trophic groups to scavenge the methanogenic substrates in ensuring the methane generation in digesters with different FW:FSS ratios. Another interesting observation was that two phylogenetically close Thermotogota species showed a possible strong competition on carbon source inferred by the nearly complete genetic overlap of their relevant pathways.
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Affiliation(s)
- Chunxiao Wang
- Environmental Microbiome Engineering and Biotechnology Laboratory, Center for Environmental Engineering Research, Department of Civil Engineering, The University of Hong Kong, Hong Kong SAR, China
| | - Yulin Wang
- Environmental Microbiome Engineering and Biotechnology Laboratory, Center for Environmental Engineering Research, Department of Civil Engineering, The University of Hong Kong, Hong Kong SAR, China; State Key Laboratory of Microbial Biotechnology, Shandong University, Qingdao 266237, China
| | - Yubo Wang
- Key Laboratory of Coastal Environment and Resources of Zhejiang Province, School of Engineering, Westlake University, 18 Shilongshan Road, Hangzhou 310024, China
| | - Lei Liu
- Environmental Microbiome Engineering and Biotechnology Laboratory, Center for Environmental Engineering Research, Department of Civil Engineering, The University of Hong Kong, Hong Kong SAR, China
| | - Dou Wang
- Environmental Microbiome Engineering and Biotechnology Laboratory, Center for Environmental Engineering Research, Department of Civil Engineering, The University of Hong Kong, Hong Kong SAR, China
| | - Feng Ju
- Key Laboratory of Coastal Environment and Resources of Zhejiang Province, School of Engineering, Westlake University, 18 Shilongshan Road, Hangzhou 310024, China
| | - Yu Xia
- State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Tong Zhang
- Environmental Microbiome Engineering and Biotechnology Laboratory, Center for Environmental Engineering Research, Department of Civil Engineering, The University of Hong Kong, Hong Kong SAR, China.
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11
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Pitta D, Indugu N, Narayan K, Hennessy M. Symposium review: Understanding the role of the rumen microbiome in enteric methane mitigation and productivity in dairy cows. J Dairy Sci 2022; 105:8569-8585. [DOI: 10.3168/jds.2021-21466] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Accepted: 02/12/2022] [Indexed: 01/01/2023]
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12
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Reconstruction and analysis of transcriptome regulatory network of Methanobrevibacter ruminantium M1. GENE REPORTS 2022. [DOI: 10.1016/j.genrep.2021.101489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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13
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Brown JL, Swift CL, Mondo SJ, Seppala S, Salamov A, Singan V, Henrissat B, Drula E, Henske JK, Lee S, LaButti K, He G, Yan M, Barry K, Grigoriev IV, O'Malley MA. Co‑cultivation of the anaerobic fungus Caecomyces churrovis with Methanobacterium bryantii enhances transcription of carbohydrate binding modules, dockerins, and pyruvate formate lyases on specific substrates. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:234. [PMID: 34893091 PMCID: PMC8665504 DOI: 10.1186/s13068-021-02083-w] [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: 08/17/2021] [Accepted: 11/19/2021] [Indexed: 05/12/2023]
Abstract
Anaerobic fungi and methanogenic archaea are two classes of microorganisms found in the rumen microbiome that metabolically interact during lignocellulose breakdown. Here, stable synthetic co-cultures of the anaerobic fungus Caecomyces churrovis and the methanogen Methanobacterium bryantii (not native to the rumen) were formed, demonstrating that microbes from different environments can be paired based on metabolic ties. Transcriptional and metabolic changes induced by methanogen co-culture were evaluated in C. churrovis across a variety of substrates to identify mechanisms that impact biomass breakdown and sugar uptake. A high-quality genome of C. churrovis was obtained and annotated, which is the first sequenced genome of a non-rhizoid-forming anaerobic fungus. C. churrovis possess an abundance of CAZymes and carbohydrate binding modules and, in agreement with previous studies of early-diverging fungal lineages, N6-methyldeoxyadenine (6mA) was associated with transcriptionally active genes. Co-culture with the methanogen increased overall transcription of CAZymes, carbohydrate binding modules, and dockerin domains in co-cultures grown on both lignocellulose and cellulose and caused upregulation of genes coding associated enzymatic machinery including carbohydrate binding modules in family 18 and dockerin domains across multiple growth substrates relative to C. churrovis monoculture. Two other fungal strains grown on a reed canary grass substrate in co-culture with the same methanogen also exhibited high log2-fold change values for upregulation of genes encoding carbohydrate binding modules in families 1 and 18. Transcriptional upregulation indicated that co-culture of the C. churrovis strain with a methanogen may enhance pyruvate formate lyase (PFL) function for growth on xylan and fructose and production of bottleneck enzymes in sugar utilization pathways, further supporting the hypothesis that co-culture with a methanogen may enhance certain fungal metabolic functions. Upregulation of CBM18 may play a role in fungal-methanogen physical associations and fungal cell wall development and remodeling.
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Affiliation(s)
- Jennifer L Brown
- Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Candice L Swift
- Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Stephen J Mondo
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Department of Agricultural Biology, Colorado State University, Fort Collins, CO, 80523, USA
| | - Susanna Seppala
- Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Asaf Salamov
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Vasanth Singan
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Bernard Henrissat
- DTU Bioengineering, Technical University of Denmark, 2800, Kgs. Lyngby, Denmark
- Department of Biological Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Elodie Drula
- Architecture Et Fonction Des Macromolécules Biologiques, CNRS/Aix-Marseille University, Marseille, France
- INRAE USC1408, AFMB, 13009, Marseille, France
| | - John K Henske
- Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Samantha Lee
- Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Kurt LaButti
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Guifen He
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Mi Yan
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Kerrie Barry
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Igor V Grigoriev
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, CA, USA
| | - Michelle A O'Malley
- Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, CA, 93106, USA.
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
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14
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Lv J, Yuan R, Wang S. Water diversion induces more changes in bacterial and archaeal communities of river sediments than seasonality. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 293:112876. [PMID: 34098351 DOI: 10.1016/j.jenvman.2021.112876] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 05/01/2021] [Accepted: 05/21/2021] [Indexed: 06/12/2023]
Abstract
Previous studies have demonstrated that seasonal variation is often the most important factor affecting aquatic bacterial assemblages. Whether anthropogenic activities can dominate community dynamics remains unknown. Based on 16S rRNA high-throughput sequencing technology, this study revealed and compared the relative influence of water diversions and seasonality on bacterial and archaeal communities in river sediments from a region with obvious seasonality. The results indicate that the influence of water diversion on bacteria and archaea in water-receiving river sediments exceeded the influence of seasonal variation. Water diversion affected microbes by increasing EC, salinity, water flow rate, and organic matter carbon and nitrogen contents. Seasonal variations affected microbes by altering water temperature. Diversion responders but no season responders were classified by statistical methods in the microbial community. Diversion responder numbers were related to nitrogen concentrations, complex organic carbon contents and EC values, which were mainly affected by water diversion. With the joint impact of water diversion and seasonality, the correlations of bacterial and archaeal numbers with environmental factors were obviously weakened due to the increases in the ecological niche breadths of microorganisms. Natural seasonal changes in bacterial and archaeal communities were totally altered by changes in salinity, nutrients, and hydrological conditions induced by anthropogenic water diversions. These results highlight that human activity may be a stronger driver than natural seasonality in the alteration of bacterial and archaeal communities.
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Affiliation(s)
- Jiali Lv
- College of Environmental and Resource Sciences, Shanxi University, Taiyuan, 030006, China; Shanxi Laboratory for Yellow River, Taiyuan, 030006, China; Key Laboratory of Agricultural Water Resources Research, Innovation Academy for Seed Design, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, 050021, China; Sino-Danish College of University of Chinese Academy of Sciences, Beijing, 101408, China; Sino-Danish Centre for Education and Research, Beijing, 101408, China
| | - Ruiqiang Yuan
- College of Environmental and Resource Sciences, Shanxi University, Taiyuan, 030006, China; Shanxi Laboratory for Yellow River, Taiyuan, 030006, China.
| | - Shiqin Wang
- Key Laboratory of Agricultural Water Resources Research, Innovation Academy for Seed Design, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, 050021, China
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15
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Formate-Dependent Heterodisulfide Reduction in a Methanomicrobiales Archaeon. Appl Environ Microbiol 2021; 87:AEM.02698-20. [PMID: 33361366 DOI: 10.1128/aem.02698-20] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 12/17/2020] [Indexed: 12/15/2022] Open
Abstract
Hydrogenotrophic methanogens produce CH4 using H2 as an electron donor to reduce CO2 In the absence of H2, many are able to use formate or alcohols as alternate electron donors. Methanogens from the order Methanomicrobiales are capable of growth with H2, but many lack genes encoding hydrogenases that are typically found in other hydrogenotrophic methanogens. In an effort to better understand electron flow in methanogens from the Methanomicrobiales, we undertook a genetic and biochemical study of heterodisulfide reductase (Hdr) in Methanoculleus thermophilus Hdr catalyzes an essential reaction by coupling the first and last steps of methanogenesis through flavin-based electron bifurcation. Hdr from M. thermophilus copurified with formate dehydrogenase (Fdh) and only displayed activity when formate was supplied as an electron donor. We found no evidence of an Hdr-associated hydrogenase, and H2 could not function as an electron donor, even with Hdr purified from cells grown on H2 We found that cells catalyze a formate hydrogenlyase activity that is likely essential for generating the formate needed for the Hdr reaction. Together, these results highlight the importance of formate as an electron donor for methanogenesis and suggest the ability to use formate is closely integrated into the methanogenic pathway in organisms from the order Methanomicrobiales IMPORTANCE Methanogens from the order Methanomicrobiales are thought to prefer H2 as an electron donor for growth. They are ubiquitous in anaerobic environments, such as in wastewater treatment facilities, anaerobic digesters, and the rumen, where they catalyze the terminal steps in the breakdown of organic matter. However, despite their importance, the metabolism of these organisms remains understudied. Using a genetic and biochemical approach, we show that formate metabolism is closely integrated into methanogenesis in Methanoculleus thermophilus This is due to a requirement for formate as the electron donor to heterodisulfide reductase (Hdr), an enzyme responsible for catalyzing essential reactions in methanogenesis by linking the initial CO2 fixing step to the exergonic terminal reaction of the pathway. These results suggest that hydrogen is not necessarily the preferred electron donor for all hydrogenotrophic methanogens and provide insight into the metabolism of methanogens from the order Methanomicrobiales.
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16
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Microbial Communities in Methane Cycle: Modern Molecular Methods Gain Insights into Their Global Ecology. ENVIRONMENTS 2021. [DOI: 10.3390/environments8020016] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The role of methane as a greenhouse gas in the concept of global climate changes is well known. Methanogens and methanotrophs are two microbial groups which contribute to the biogeochemical methane cycle in soil, so that the total emission of CH4 is the balance between its production and oxidation by microbial communities. Traditional identification techniques, such as selective enrichment and pure-culture isolation, have been used for a long time to study diversity of methanogens and methanotrophs. However, these techniques are characterized by significant limitations, since only a relatively small fraction of the microbial community could be cultured. Modern molecular methods for quantitative analysis of the microbial community such as real-time PCR (Polymerase chain reaction), DNA fingerprints and methods based on high-throughput sequencing together with different “omics” techniques overcome the limitations imposed by culture-dependent approaches and provide new insights into the diversity and ecology of microbial communities in the methane cycle. Here, we review available knowledge concerning the abundances, composition, and activity of methanogenic and methanotrophic communities in a wide range of natural and anthropogenic environments. We suggest that incorporation of microbial data could fill the existing microbiological gaps in methane flux modeling, and significantly increase the predictive power of models for different environments.
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17
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Muturi SM, Muthui LW, Njogu PM, Onguso JM, Wachira FN, Opiyo SO, Pelle R. Metagenomics survey unravels diversity of biogas microbiomes with potential to enhance productivity in Kenya. PLoS One 2021; 16:e0244755. [PMID: 33395690 PMCID: PMC7781671 DOI: 10.1371/journal.pone.0244755] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 12/16/2020] [Indexed: 12/27/2022] Open
Abstract
The obstacle to optimal utilization of biogas technology is poor understanding of biogas microbiomes diversities over a wide geographical coverage. We performed random shotgun sequencing on twelve environmental samples. Randomized complete block design was utilized to assign the twelve treatments to four blocks, within eastern and central regions of Kenya. We obtained 42 million paired-end reads that were annotated against sixteen reference databases using two ENVO ontologies, prior to β-diversity studies. We identified 37 phyla, 65 classes and 132 orders. Bacteria dominated and comprised 28 phyla, 42 classes and 92 orders, conveying substrate's versatility in the treatments. Though, Fungi and Archaea comprised 5 phyla, the Fungi were richer; suggesting the importance of hydrolysis and fermentation in biogas production. High β-diversity within the taxa was largely linked to communities' metabolic capabilities. Clostridiales and Bacteroidales, the most prevalent guilds, metabolize organic macromolecules. The identified Cytophagales, Alteromonadales, Flavobacteriales, Fusobacteriales, Deferribacterales, Elusimicrobiales, Chlamydiales, Synergistales to mention but few, also catabolize macromolecules into smaller substrates to conserve energy. Furthermore, δ-Proteobacteria, Gloeobacteria and Clostridia affiliates syntrophically regulate PH2 and reduce metal to provide reducing equivalents. Methanomicrobiales and other Methanomicrobia species were the most prevalence Archaea, converting formate, CO2(g), acetate and methylated substrates into CH4(g). Thermococci, Thermoplasmata and Thermoprotei were among the sulfur and other metal reducing Archaea that contributed to redox balancing and other metabolism within treatments. Eukaryotes, mainly fungi were the least abundant guild, comprising largely Ascomycota and Basidiomycota species. Chytridiomycetes, Blastocladiomycetes and Mortierellomycetes were among the rare species, suggesting their metabolic and substrates limitations. Generally, we observed that environmental and treatment perturbations influenced communities' abundance, β-diversity and reactor performance largely through stochastic effect. Understanding diversity of biogas microbiomes over wide environmental variables and its' productivity provided insights into better management strategies that ameliorate biochemical limitations to effective biogas production.
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Affiliation(s)
- Samuel Mwangangi Muturi
- Department of Biological Sciences, University of Eldoret, Eldoret, Kenya
- Institute for Bioteschnology Research, Jomo Kenyatta University of Agriculture and Technology, Juja, Kenya
| | - Lucy Wangui Muthui
- Biosciences Eastern and Central Africa—International Livestock Research Institute (BecA-ILRI) Hub, Nairobi, Kenya
| | - Paul Mwangi Njogu
- Institute for Energy and Environmental Technology, Jomo Kenyatta University of Agriculture and Technology, Juja, Kenya
| | - Justus Mong’are Onguso
- Institute for Bioteschnology Research, Jomo Kenyatta University of Agriculture and Technology, Juja, Kenya
| | | | - Stephen Obol Opiyo
- OARDC, Molecular and Cellular Imaging Center-Columbus, Ohio State University, Columbus, Ohio, United States of America
- The University of Sacread Heart, Gulu, Uganda
| | - Roger Pelle
- Biosciences Eastern and Central Africa—International Livestock Research Institute (BecA-ILRI) Hub, Nairobi, Kenya
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18
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Euler S, Jeffrey LC, Maher DT, Mackenzie D, Tait DR. Shifts in methanogenic archaea communities and methane dynamics along a subtropical estuarine land use gradient. PLoS One 2020; 15:e0242339. [PMID: 33232349 PMCID: PMC7685437 DOI: 10.1371/journal.pone.0242339] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 10/30/2020] [Indexed: 02/01/2023] Open
Abstract
In coastal aquatic ecosystems, prokaryotic communities play an important role in regulating the cycling of nutrients and greenhouse gases. In the coastal zone, estuaries are complex and delicately balanced systems containing a multitude of specific ecological niches for resident microbes. Anthropogenic influences (i.e. urban, industrial and agricultural land uses) along the estuarine continuum can invoke physical and biochemical changes that impact these niches. In this study, we investigate the relative abundance of methanogenic archaea and other prokaryotic communities, distributed along a land use gradient in the subtropical Burnett River Estuary, situated within the Great Barrier Reef catchment, Australia. Microbiological assemblages were compared to physicochemical, nutrient and greenhouse gas distributions in both pore and surface water. Pore water samples from within the most urbanised site showed a high relative abundance of methanogenic Euryarchaeota (7.8% of all detected prokaryotes), which coincided with elevated methane concentrations in the water column, ranging from 0.51 to 0.68 μM at the urban and sewage treatment plant (STP) sites, respectively. These sites also featured elevated dissolved organic carbon (DOC) concentrations (0.66 to 1.16 mM), potentially fuelling methanogenesis. At the upstream freshwater site, both methane and DOC concentrations were considerably higher (2.68 μM and 1.8 mM respectively) than at the estuarine sites (0.02 to 0.66 μM and 0.39 to 1.16 mM respectively) and corresponded to the highest relative abundance of methanotrophic bacteria. The proportion of sulfate reducing bacteria in the prokaryotic community was elevated within the urban and STP sites (relative abundances of 8.0%– 10.5%), consistent with electron acceptors with higher redox potentials (e.g. O2, NO3-) being scarce. Overall, this study showed that ecological niches in anthropogenically altered environments appear to give an advantage to specialized prokaryotes invoking a potential change in the thermodynamic landscape of the ecosystem and in turn facilitating the generation of methane–a potent greenhouse gas.
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Affiliation(s)
- Sebastian Euler
- SCU GeoScience, Southern Cross University, Lismore, NSW, Australia
- * E-mail: ,
| | - Luke C. Jeffrey
- SCU GeoScience, Southern Cross University, Lismore, NSW, Australia
| | - Damien T. Maher
- SCU GeoScience, Southern Cross University, Lismore, NSW, Australia
- School of Environment, Science and Engineering, Southern Cross University, Lismore, NSW, Australia
| | - Derek Mackenzie
- SCU GeoScience, Southern Cross University, Lismore, NSW, Australia
| | - Douglas R. Tait
- SCU GeoScience, Southern Cross University, Lismore, NSW, Australia
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19
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Mahmod SS, Azahar AM, Luthfi AAI, Abdul PM, Mastar MS, Anuar N, Takriff MS, Jahim JMD. Potential Utilisation of Dark-Fermented Palm Oil Mill Effluent in Continuous Production of Biomethane by Self-Granulated Mixed Culture. Sci Rep 2020; 10:9167. [PMID: 32514030 PMCID: PMC7280187 DOI: 10.1038/s41598-020-65702-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2020] [Accepted: 04/22/2020] [Indexed: 01/03/2023] Open
Abstract
Two-stage anaerobic digestion of palm oil mill effluent (POME) is a promising method for converting the waste from the largest agricultural industry in Southeast Asia into a clean and sustainable energy. This study investigates the degradation of acid-rich effluent from the dark fermentation stage for the production of biomethane (BioCH4) in a 30-L continuous stirred-tank reactor (CSTR). The continuous methanogenic process was operated with varied HRTs (10 - 1 day) and OLRs (4.6-40.6 gCOD/L.d-1) under thermophilic conditions. Methanothermobacter sp. was the dominant thermophilic archaea that was responsible for the production rate of 4.3 LCH4/LPOME.d-1 and methane yield of 256.77 LCH4kgCOD at HRT of 2 d, which is the lowest HRT reported in the literature. The process was able to digest 85% and 64% of the initial POME's COD and TSS, respectively. The formation of methane producing granules (MPG) played a pivotal role in sustaining the efficient and productive anaerobic system. We report herein that the anaerobic digestion was not only beneficial in reducing the contaminants in the liquid effluent, but generating BioCH4 gas with a positive net energy gain of 7.6 kJ/gCOD.
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Affiliation(s)
- Safa Senan Mahmod
- Research Centre for Sustainable Process Technology (CESPRO), Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, UKM Bangi, Selangor, Malaysia
| | - Azratul Madihah Azahar
- Research Centre for Sustainable Process Technology (CESPRO), Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, UKM Bangi, Selangor, Malaysia
| | - Abdullah Amru Indera Luthfi
- Research Centre for Sustainable Process Technology (CESPRO), Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, UKM Bangi, Selangor, Malaysia
| | - Peer Mohamed Abdul
- Research Centre for Sustainable Process Technology (CESPRO), Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, UKM Bangi, Selangor, Malaysia
- Chemical Engineering Programme, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor, Malaysia
| | - Mohd Shahbudin Mastar
- Research Centre for Sustainable Process Technology (CESPRO), Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, UKM Bangi, Selangor, Malaysia
- Chemical Engineering Programme, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor, Malaysia
| | - Nurina Anuar
- Research Centre for Sustainable Process Technology (CESPRO), Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, UKM Bangi, Selangor, Malaysia
- Chemical Engineering Programme, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor, Malaysia
| | - Mohd Sobri Takriff
- Research Centre for Sustainable Process Technology (CESPRO), Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, UKM Bangi, Selangor, Malaysia
- Chemical Engineering Programme, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor, Malaysia
| | - Jamaliah M D Jahim
- Research Centre for Sustainable Process Technology (CESPRO), Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, UKM Bangi, Selangor, Malaysia.
- Chemical Engineering Programme, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor, Malaysia.
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20
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Biderre-Petit C, Taib N, Gardon H, Hochart C, Debroas D. New insights into the pelagic microorganisms involved in the methane cycle in the meromictic Lake Pavin through metagenomics. FEMS Microbiol Ecol 2020; 95:5092586. [PMID: 30203066 DOI: 10.1093/femsec/fiy183] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 09/06/2018] [Indexed: 11/13/2022] Open
Abstract
Advances in metagenomics have given rise to the possibility of obtaining genome sequences from uncultured microorganisms, even for those poorly represented in the microbial community, thereby providing an important means to study their ecology and evolution. In this study, metagenomic sequencing was carried out at four sampling depths having different oxygen concentrations or environmental conditions in the water column of Lake Pavin. By analyzing the sequenced reads and matching the contigs to the proxy genomes of the closest cultivated relatives, we evaluated the metabolic potential of the dominant planktonic species involved in the methane cycle. We demonstrated that methane-producing communities were dominated by the genus Methanoregula while methane-consuming communities were dominated by the genus Methylobacter, thus confirming prior observations. Our work allowed the reconstruction of a draft of their core metabolic pathways. Hydrogenotrophs, the genes required for acetate activation in the methanogen genome, were also detected. Regarding methanotrophy, Methylobacter was present in the same areas as the non-methanotrophic, methylotrophic Methylotenera, which could suggest a relationship between these two groups. Furthermore, the presence of a large gene inventory for nitrogen metabolism (nitrate transport, denitrification, nitrite assimilation and nitrogen fixation, for instance) was detected in the Methylobacter genome.
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Affiliation(s)
- Corinne Biderre-Petit
- Université Clermont Auvergne, CNRS, Laboratoire Microorganismes: Génome et Environnement, F-63000 Clermont-Ferrand, France
| | - Najwa Taib
- Université Clermont Auvergne, CNRS, Laboratoire Microorganismes: Génome et Environnement, F-63000 Clermont-Ferrand, France
| | - Hélène Gardon
- Université Clermont Auvergne, CNRS, Laboratoire Microorganismes: Génome et Environnement, F-63000 Clermont-Ferrand, France
| | - Corentin Hochart
- Université Clermont Auvergne, CNRS, Laboratoire Microorganismes: Génome et Environnement, F-63000 Clermont-Ferrand, France
| | - Didier Debroas
- Université Clermont Auvergne, CNRS, Laboratoire Microorganismes: Génome et Environnement, F-63000 Clermont-Ferrand, France
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21
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Macaulay BM, Boothman C, van Dongen BE, Lloyd JR. A Novel "Microbial Bait" Technique for Capturing Fe(III)-Reducing Bacteria. Front Microbiol 2020; 11:330. [PMID: 32218773 PMCID: PMC7078115 DOI: 10.3389/fmicb.2020.00330] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 02/14/2020] [Indexed: 11/29/2022] Open
Abstract
Microbial reduction of Fe(III) is a key geochemical process in anoxic environments, controlling the degradation of organics and the mobility of metals and radionuclides. To further understand these processes, it is vital to develop a reliable means of capturing Fe(III)-reducing microorganisms from the field for analysis and lab-based investigations. In this study, a novel method of capturing Fe(III)-reducing bacteria using Fe(III)-coated pumice "microbe-baits" was demonstrated. The methodology involved the coating of pumice (approximately diameter 4 to 6 mm) with a bioavailable Fe(III) mineral (akaganeite), and was verified by deployment into a freshwater spring for 2 months. On retrieval, the coated pumice baits were incubated in a series of lab-based microcosms, amended with and without electron donors (lactate and acetate), and incubated at 20°C for 8 weeks. 16S rRNA gene sequencing using the Illumina MiSeq platform showed that the Fe(III)-coated pumice baits, when incubated in the presence of lactate and acetate, enriched for Deltaproteobacteria (relative abundance of 52% of the sequences detected corresponded to Geobacter species and 24% to Desulfovibrio species). In the absence of added electron donors, Betaproteobacteria were the most abundant class detected, most heavily represented by a close relative to Rhodoferax ferrireducens (15% of species detected), that most likely used organic matter sequestered from the spring waters to support Fe(III) reduction. In addition, TEM-EDS analysis of the Fe(III)-coated pumice slurries amended with electron donors revealed that a biogenic Fe(II) mineral, magnetite, was formed at the end of the incubation period. These results demonstrate that Fe(III)-coated pumice "microbe baits" can potentially help target metal-reducing bacteria for culture-dependent studies, to further our understanding of the nano-scale microbe-mineral interactions in aquifers.
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Affiliation(s)
- Babajide Milton Macaulay
- Department of Earth and Environmental Sciences, The University of Manchester, Manchester, United Kingdom
- Williamson Research Centre for Molecular Environmental Science, The University of Manchester, Manchester, United Kingdom
- Environmental Biology and Public Health Unit, Department of Biology, The Federal University of Technology, Akure, Nigeria
| | - Christopher Boothman
- Department of Earth and Environmental Sciences, The University of Manchester, Manchester, United Kingdom
- Williamson Research Centre for Molecular Environmental Science, The University of Manchester, Manchester, United Kingdom
| | - Bart E. van Dongen
- Department of Earth and Environmental Sciences, The University of Manchester, Manchester, United Kingdom
- Williamson Research Centre for Molecular Environmental Science, The University of Manchester, Manchester, United Kingdom
| | - Jonathan Richard Lloyd
- Department of Earth and Environmental Sciences, The University of Manchester, Manchester, United Kingdom
- Williamson Research Centre for Molecular Environmental Science, The University of Manchester, Manchester, United Kingdom
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22
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Direct Electron Transfer between the frhAGB-Encoded Hydrogenase and Thioredoxin Reductase in the Nonmethanogenic Archaeon Thermococcus onnurineus NA1. Appl Environ Microbiol 2020; 86:AEM.02630-19. [PMID: 31924613 DOI: 10.1128/aem.02630-19] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 12/21/2019] [Indexed: 11/20/2022] Open
Abstract
To date, NAD(P)H, ferredoxin, and coenzyme F420 have been identified as electron donors for thioredoxin reductase (TrxR). In this study, we present a novel electron source for TrxR. In the hyperthermophilic archaeon Thermococcus onnurineus NA1, the frhAGB-encoded hydrogenase, a homolog of the F420-reducing hydrogenase of methanogens, was demonstrated to interact with TrxR in coimmunoprecipitation experiments and in vitro pulldown assays. Electrons derived from H2 oxidation by the frhAGB-encoded hydrogenase were transferred to TrxR and reduced Pdo, a redox partner of TrxR. Interaction and electron transfer were observed between TrxR and the heterodimeric hydrogenase complex (FrhAG) as well as the heterotrimeric complex (FrhAGB). Hydrogen-dependent reduction of TrxR was 7-fold less efficient than when NADPH was the electron donor. This study not only presents a different type of electron donor for TrxR but also reveals new functionality of the frhAGB-encoded hydrogenase utilizing a protein as an electron acceptor.IMPORTANCE This study has importance in that TrxR can use H2 as an electron donor with the aid of the frhAGB-encoded hydrogenase as well as NAD(P)H in T. onnurineus NA1. Further studies are needed to explore the physiological significance of this protein. This study also has importance as a significant step toward understanding the functionality of the frhAGB-encoded hydrogenase in a nonmethanogen; the hydrogenase can transfer electrons derived from oxidation of H2 to a protein target by direct contact without the involvement of an electron carrier, which is distinct from the mechanism of its homologs, F420-reducing hydrogenases of methanogens.
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Nguyen D, Wu Z, Shrestha S, Lee PH, Raskin L, Khanal SK. Intermittent micro-aeration: New strategy to control volatile fatty acid accumulation in high organic loading anaerobic digestion. WATER RESEARCH 2019; 166:115080. [PMID: 31541792 DOI: 10.1016/j.watres.2019.115080] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 09/02/2019] [Accepted: 09/10/2019] [Indexed: 05/11/2023]
Abstract
This study developed an intermittent oxidation-reduction potential (ORP)-controlled micro-aeration system for high solids anaerobic digestion (AD) of lignocellulosic biomass without volatile fatty acids (VFA) accumulation at high organic loading rate (OLR). Traditional AD of Napier grass, a model lignocellulosic biomass, at an OLR of 5 g volatile solids (VS)/L/day resulted in an accumulation of total VFA concentration up to 9.2 g/L as acetic acid (HAc) equivalent, causing rapid drops in pH and methane yield, and driving the digester to the verge of failure. Once intermittent (every 24 h) ORP-controlled micro-aeration (at ORP of -470 mV) was initiated, the total VFA concentration rapidly decreased to 3.0 g HAc/L and the methane yield improved, resulting in stable digester performance without the need for alkalinity supplementation or OLR reduction. By combining reactor performance results, mass balance analyses, microbial community characterization data, and a bioenergetic evaluation, this study suggested that rapid VFA conversion and CH4 production were carried out by facultative anaerobes and hydrogenotrophic methanogens under micro-aerobic conditions. This novel operating approach can be applied as an effective control strategy for high OLR AD processes especially in the event of VFA accumulation.
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Affiliation(s)
- Duc Nguyen
- Department of Molecular Biosciences and Bioengineering, University of Hawai'i at Mānoa, Honolulu, HI, 96822, USA
| | - Zhuoying Wu
- Department of Civil and Environmental Engineering, Imperial College, London, United Kingdom
| | - Shilva Shrestha
- Department of Civil and Environmental Engineering, University of Michigan, 1351 Beal Avenue, 107 EWRE Building, Ann Arbor, MI, 48109-2125, USA
| | - Po-Heng Lee
- Department of Civil and Environmental Engineering, Imperial College, London, United Kingdom
| | - Lutgarde Raskin
- Department of Civil and Environmental Engineering, University of Michigan, 1351 Beal Avenue, 107 EWRE Building, Ann Arbor, MI, 48109-2125, USA
| | - Samir Kumar Khanal
- Department of Molecular Biosciences and Bioengineering, University of Hawai'i at Mānoa, Honolulu, HI, 96822, USA.
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Lillington SP, Leggieri PA, Heom KA, O'Malley MA. Nature's recyclers: anaerobic microbial communities drive crude biomass deconstruction. Curr Opin Biotechnol 2019; 62:38-47. [PMID: 31593910 DOI: 10.1016/j.copbio.2019.08.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 08/25/2019] [Accepted: 08/29/2019] [Indexed: 12/13/2022]
Abstract
Microbial communities within anaerobic ecosystems have evolved to degrade and recycle carbon throughout the earth. A number of strains have been isolated from anaerobic microbial communities, which are rich in carbohydrate active enzymes (CAZymes) to liberate fermentable sugars from crude plant biomass (lignocellulose). However, natural anaerobic communities host a wealth of microbial diversity that has yet to be harnessed for biotechnological applications to hydrolyze crude biomass into sugars and value-added products. This review highlights recent advances in 'omics' techniques to sequence anaerobic microbial genomes, decipher microbial membership, and characterize CAZyme diversity in anaerobic microbiomes. With a focus on the herbivore rumen, we further discuss methods to discover new CAZymes, including those found within multi-enzyme fungal cellulosomes. Emerging techniques to characterize the interwoven metabolism and spatial interactions between anaerobes are also reviewed, which will prove critical to developing a predictive understanding of anaerobic communities to guide in microbiome engineering.
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Affiliation(s)
- Stephen P Lillington
- Department of Chemical Engineering, University of California, Santa Barbara, CA 93106, United States
| | - Patrick A Leggieri
- Department of Chemical Engineering, University of California, Santa Barbara, CA 93106, United States
| | - Kellie A Heom
- Department of Chemical Engineering, University of California, Santa Barbara, CA 93106, United States
| | - Michelle A O'Malley
- Department of Chemical Engineering, University of California, Santa Barbara, CA 93106, United States.
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Zhao Y, Xu C, Ai S, Wang H, Gao Y, Yan L, Mei Z, Wang W. Biological pretreatment enhances the activity of functional microorganisms and the ability of methanogenesis during anaerobic digestion. BIORESOURCE TECHNOLOGY 2019; 290:121660. [PMID: 31326651 DOI: 10.1016/j.biortech.2019.121660] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 06/13/2019] [Accepted: 06/15/2019] [Indexed: 06/10/2023]
Abstract
Biological pretreatment can increase the methane production of anaerobic digestion. In this study, stover was pretreated via microbial consortium prior to anaerobic digestion; through 16S rRNA gene and 16S rRNA amplicon sequencing and metatranscriptomic analysis, and the effects of the pretreatment on the microbial community and critical factors of the increased methane production were studied. Microbial community structure was less affected by the pretreatment, which ensures the stable performance of anaerobic digestion. The methane production increased by 62.85% at the peak phase compared to the untreated stover. The activity of Methanosaeta increased from 2.0% to 10.1%, significantly enhancing the ability of the community to capture acetic acid and reduce CO2 to methane. The main contribution to the increase in methane production was a unique acetyl-CoA synthetase, which showed significant up-regulation (121.8%). This research demonstrated the importance of Methanosaeta and its unique metabolic pathways in anaerobic digestion utilizing a biological pretreatment.
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Affiliation(s)
- Yiquan Zhao
- Heilongjiang Provincial Key Laboratory of Environmental Microbiology and Recycling of Argo-Waste in Cold Region, College of Life Science and Technology, Heilongjiang Bayi Agricultural University, Daqing 163319, PR China
| | - Congfeng Xu
- Heilongjiang Provincial Key Laboratory of Environmental Microbiology and Recycling of Argo-Waste in Cold Region, College of Life Science and Technology, Heilongjiang Bayi Agricultural University, Daqing 163319, PR China
| | - Shiqi Ai
- Heilongjiang Provincial Key Laboratory of Environmental Microbiology and Recycling of Argo-Waste in Cold Region, College of Life Science and Technology, Heilongjiang Bayi Agricultural University, Daqing 163319, PR China
| | - Haipeng Wang
- Heilongjiang Provincial Key Laboratory of Environmental Microbiology and Recycling of Argo-Waste in Cold Region, College of Life Science and Technology, Heilongjiang Bayi Agricultural University, Daqing 163319, PR China
| | - Yamei Gao
- Heilongjiang Provincial Key Laboratory of Environmental Microbiology and Recycling of Argo-Waste in Cold Region, College of Life Science and Technology, Heilongjiang Bayi Agricultural University, Daqing 163319, PR China
| | - Lei Yan
- Heilongjiang Provincial Key Laboratory of Environmental Microbiology and Recycling of Argo-Waste in Cold Region, College of Life Science and Technology, Heilongjiang Bayi Agricultural University, Daqing 163319, PR China
| | - Zili Mei
- Biogas Institute of Ministry of Agriculture and Rural Affairs, 610041 Chengdu, PR China
| | - Weidong Wang
- Heilongjiang Provincial Key Laboratory of Environmental Microbiology and Recycling of Argo-Waste in Cold Region, College of Life Science and Technology, Heilongjiang Bayi Agricultural University, Daqing 163319, PR China.
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Gilmore SP, Lankiewicz TS, Wilken SE, Brown JL, Sexton JA, Henske JK, Theodorou MK, Valentine DL, O’Malley MA. Top-Down Enrichment Guides in Formation of Synthetic Microbial Consortia for Biomass Degradation. ACS Synth Biol 2019; 8:2174-2185. [PMID: 31461261 DOI: 10.1021/acssynbio.9b00271] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Consortium-based approaches are a promising avenue toward efficient bioprocessing. However, many complex microbial interactions dictate community dynamics and stability that must be replicated in synthetic systems. The rumen and/or hindguts of large mammalian herbivores harbor complex communities of biomass-degrading fungi and bacteria, as well as archaea and protozoa that work collectively to degrade lignocellulose, yet the microbial interactions responsible for stability, resilience, and activity of the community remain largely uncharacterized. In this work, we demonstrate a "top-down" enrichment-based methodology for selecting a minimal but effective lignocellulose-degrading community that produces methane-rich fermentation gas (biogas). The resulting enrichment consortium produced 0.75-1.9-fold more fermentation gas at 1.4-2.1 times the rate compared to a monoculture of fungi from the enrichment. Metagenomic sequencing of the top-down enriched consortium revealed genomes encoding for functional compartmentalization of the community, spread across an anaerobic fungus (Piromyces), a bacterium (Sphaerochaeta), and two methanogenic archaea (Methanosphaera and Methanocorpusculum). Guided by the composition of the top-down enrichment, several synthetic cocultures were formed from the "bottom-up" using previously isolated fungi, Neocallimastix californiae and Anaeromyces robustus paired with the methanogen Methanobacterium bryantii. While cross-feeding occurred in synthetic co-cultures, removal of fungal metabolites by methanogens did not increase the rate of gas production or the rate of substrate deconstruction by the synthetic community relative to fungal monocultures. Metabolomic characterization verified that syntrophy was established within synthetic co-cultures, which generated methane at similar concentrations compared to the enriched consortium but lacked the temporal stability (resilience) seen in the native system. Taken together, deciphering the membership and metabolic potential of an enriched gut consortium enables the design of methanogenic synthetic co-cultures. However, differences in the growth rate and stability of enriched versus synthetic consortia underscore the difficulties in mimicking naturally occurring syntrophy in synthetic systems.
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Affiliation(s)
- Sean P. Gilmore
- Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, California 93106, United States
| | - Thomas S. Lankiewicz
- Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, California 93106, United States
- Department of Ecology, Evolution, and Marine Biology, University of California Santa Barbara, Santa Barbara, California 93106, United States
| | - St. Elmo Wilken
- Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, California 93106, United States
| | - Jennifer L. Brown
- Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, California 93106, United States
| | - Jessica A. Sexton
- Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, California 93106, United States
| | - John K. Henske
- Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, California 93106, United States
| | - Michael K. Theodorou
- Harper Adams University, Agriculture Centre for Sustainable Energy Systems, Newport, Shropshire TF10 8NB, United Kingdom
| | - David L. Valentine
- Department of Earth Science and Marine Science Institute, University of California Santa Barbara, Santa Barbara, California 93106, United States
| | - Michelle A. O’Malley
- Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, California 93106, United States
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Fernández-Martínez MÁ, dos Santos Severino R, Moreno-Paz M, Gallardo-Carreño I, Blanco Y, Warren-Rhodes K, García-Villadangos M, Ruiz-Bermejo M, Barberán A, Wettergreen D, Cabrol N, Parro V. Prokaryotic Community Structure and Metabolisms in Shallow Subsurface of Atacama Desert Playas and Alluvial Fans After Heavy Rains: Repairing and Preparing for Next Dry Period. Front Microbiol 2019; 10:1641. [PMID: 31396176 PMCID: PMC6668633 DOI: 10.3389/fmicb.2019.01641] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 07/02/2019] [Indexed: 11/13/2022] Open
Abstract
The Atacama Desert, the oldest and driest desert on Earth, displays significant rains only once per decade. To investigate how microbial communities take advantage of these sporadic wet events, we carried out a geomicrobiological study a few days after a heavy rain event in 2015. Different physicochemical and microbial community analyses were conducted on samples collected from playas and an alluvial fan from surface, 10, 20, 50, and 80 cm depth. Gravimetric moisture content peaks were measured in 10 and 20 cm depth samples (from 1.65 to 4.1% w/w maximum values) while, in general, main anions such as chloride, nitrate, and sulfate concentrations increased with depth, with maximum values of 13-1,125; 168-10,109; and 9,904-30,952 ppm, respectively. Small organic anions such as formate and acetate had maximum concentrations from 2.61 to 3.44 ppm and 6.73 to 28.75 ppm, respectively. Microbial diversity inferred from DNA analysis showed Actinobacteria and Alphaproteobacteria as the most abundant and widespread bacterial taxa among the samples, followed by Chloroflexi and Firmicutes at specific sites. Archaea were mainly dominated by Nitrososphaerales, Methanobacteria, with the detection of other groups such as Halobacteria. Metaproteomics showed a high and even distribution of proteins involved in primary metabolic processes such as energy production and biosynthetic pathways, and a limited but remarkable presence of proteins related to resistance to environmental stressors such as radiation, oxidation, or desiccation. The results indicated that extra humidity in the system allows the microbial community to repair, and prepare for the upcoming hyperarid period. Additionally, it supplies biomarkers to the medium whose preservation potential could be high under strong desiccation conditions and relevant for planetary exploration.
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Affiliation(s)
| | | | | | | | | | - Kimberley Warren-Rhodes
- Carl Sagan Center, SETI Institute, Mountain View, CA, United States
- NASA Ames Research Center, Moffett Field, Mountain View, CA, United States
| | | | | | - Albert Barberán
- Department of Soil, Water, and Environmental Science, University of Arizona, Tucson, AZ, United States
| | - David Wettergreen
- Carnegie Mellon University, Robotics Institute, Pittsburgh, PA, United States
| | - Nathalie Cabrol
- Carl Sagan Center, SETI Institute, Mountain View, CA, United States
- NASA Ames Research Center, Moffett Field, Mountain View, CA, United States
| | - Víctor Parro
- Centro de Astrobiología (CAB, CSIC-INTA), Madrid, Spain
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28
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Heterogeneous development of methanogens and the correlation with bacteria in the rumen and cecum of sika deer (Cervus nippon) during early life suggest different ecology relevance. BMC Microbiol 2019; 19:129. [PMID: 31185894 PMCID: PMC6560721 DOI: 10.1186/s12866-019-1504-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 05/31/2019] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND Enteric methane from the ruminant livestock is a significant source in global greenhouse gas emissions, which is mainly generated by the methanogens inhabiting the rumen and cecum. Sika deer (Cervus nippon) not only produces less methane than bovine, but they also harbor a distinct methanogen community. Whereas, knowledge of methanogens colonization in the rumen and cecum of sika deer is relatively still unknown, which could provide more insights to the manipulation of gut microbiota during early life. RESULTS Here, we examined the development of bacteria and methanogens in the rumen and cecum of juvenile sika deer from birth to post-weaning (1 day, 42 days and 70 days, respectively) based on next generation sequencing. The results showed that the facultative anaerobic bacteria were decreased and the cellulolytic bacteria were increased. However, methanogens established soon after birth thrived through the whole developmental period, indicating a different succession process than bacteria in the GIT, and the limited role of age and dietary change on GIT methanogens. We also found Methanobrevibacter spp. (Mean relative abundance = 44.2%) and Methanocorpusculum spp. (Mean relative abundance = 57.5%) were dominated in the rumen and cecum, respectively. The methanogens also formed specific correlations with bacteria under different niches, suggesting a role of ecology niche on methanogen community. CONCLUSIONS This study contributes to our knowledge about the microbial succession in GIT of sika deer, that may facilitate the development of targeted strategies to improve GIT function of sika deer.
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Co-cultivation of the anaerobic fungus Anaeromyces robustus with Methanobacterium bryantii enhances transcription of carbohydrate active enzymes. J Ind Microbiol Biotechnol 2019; 46:1427-1433. [PMID: 31089985 DOI: 10.1007/s10295-019-02188-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 05/07/2019] [Indexed: 12/18/2022]
Abstract
Anaerobic gut fungi are biomass degraders that form syntrophic associations with other microbes in their native rumen environment. Here, RNA-Seq was used to track and quantify carbohydrate active enzyme (CAZyme) transcription in a synthetic consortium composed of the anaerobic fungus Anaeromyces robustus with methanogen Methanobacterium bryantii. Approximately 5% of total A. robustus genes were differentially regulated in co-culture with M. bryantii relative to cultivation of A. robustus alone. We found that 105 CAZymes (12% of the total predicted CAZymes of A. robustus) were upregulated while 29 were downregulated. Upregulated genes encode putative proteins with a wide array of cellulolytic, xylanolytic, and carbohydrate transport activities; 75% were fused to fungal dockerin domains, associated with a carbohydrate binding module, or both. Collectively, this analysis suggests that co-culture of A. robustus with M. bryantii remodels the transcriptional landscape of CAZymes and associated metabolic pathways in the fungus to aid in lignocellulose breakdown.
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30
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Comparative Genomic Analysis of Members of the Genera Methanosphaera and Methanobrevibacter Reveals Distinct Clades with Specific Potential Metabolic Functions. ARCHAEA-AN INTERNATIONAL MICROBIOLOGICAL JOURNAL 2018; 2018:7609847. [PMID: 30210264 PMCID: PMC6120340 DOI: 10.1155/2018/7609847] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 07/02/2018] [Indexed: 12/11/2022]
Abstract
Methanobrevibacter and Methanosphaera species represent some of the most prevalent methanogenic archaea in the gastrointestinal tract of animals and humans and play an important role in this environment. The aim of this study was to identify genomic features that are shared or specific for members of each genus with a special emphasis of the analysis on the assimilation of nitrogen and acetate and the utilization of methanol and ethanol for methanogenesis. Here, draft genome sequences of Methanobrevibacter thaueri strain DSM 11995T, Methanobrevibacter woesei strain DSM 11979T, and Methanosphaera cuniculi strain 4103T are reported and compared to those of 16 other Methanobrevibacter and Methanosphaera genomes, including genomes of the 13 currently available types of strains of the two genera. The comparative genome analyses indicate that among other genes, the absence of molybdopterin cofactor biosynthesis is conserved in Methanosphaera species but reveals also that the three species share a core set of more than 300 genes that distinguishes the genus Methanosphaera from the genus Methanobrevibacter. Multilocus sequence analysis shows that the genus Methanobrevibacter can be subdivided into clades, potentially new genera, which may display characteristic specific metabolic features. These features include not only the potential ability of nitrogen fixation and acetate assimilation in a clade comprised of Methanobrevibacter species from the termite gut and Methanobrevibacter arboriphilus strains but also the potential capability to utilize ethanol and methanol in a clade comprising Methanobrevibacter wolinii strain DSM 11976T, Mbb. sp. AbM4, and Mbb. boviskoreani strain DSM 25824T.
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Hoedt EC, Parks DH, Volmer JG, Rosewarne CP, Denman SE, McSweeney CS, Muir JG, Gibson PR, Cuív PÓ, Hugenholtz P, Tyson GW, Morrison M. Culture- and metagenomics-enabled analyses of the Methanosphaera genus reveals their monophyletic origin and differentiation according to genome size. ISME JOURNAL 2018; 12:2942-2953. [PMID: 30068938 DOI: 10.1038/s41396-018-0225-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 04/27/2018] [Accepted: 06/03/2018] [Indexed: 11/09/2022]
Abstract
The genus Methanosphaera is a well-recognized but poorly characterized member of the mammalian gut microbiome, and distinctive from Methanobrevibacter smithii for its ability to induce a pro-inflammatory response in humans. Here we have used a combination of culture- and metagenomics-based approaches to expand the representation and information for the genus, which has supported the examination of their phylogeny and physiological capacity. Novel isolates of the genus Methanosphaera were recovered from bovine rumen digesta and human stool, with the bovine isolate remarkable for its large genome size relative to other Methanosphaera isolates from monogastric hosts. To substantiate this observation, we then recovered seven high-quality Methanosphaera-affiliated population genomes from ruminant and human gut metagenomic datasets. Our analyses confirm a monophyletic origin of Methanosphaera spp. and that the colonization of monogastric and ruminant hosts favors representatives of the genus with different genome sizes, reflecting differences in the genome content needed to persist in these different habitats.
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Affiliation(s)
- Emily C Hoedt
- The University of Queensland Diamantina Institute, Translational Research Institute, Brisbane, Queensland, Australia
| | - Donovan H Parks
- Australian Centre for Ecogenomics, The University of Queensland, St Lucia, Australia.,School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
| | - James G Volmer
- The University of Queensland Diamantina Institute, Translational Research Institute, Brisbane, Queensland, Australia.,School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
| | - Carly P Rosewarne
- Commonwealth Scientific and Industrial Research Organisation, Kintore Avenue, Adelaide, Australia
| | - Stuart E Denman
- Commonwealth Scientific and Industrial Research Organisation, Queensland Bioscience Precinct, St Lucia, Australia
| | - Christopher S McSweeney
- Commonwealth Scientific and Industrial Research Organisation, Queensland Bioscience Precinct, St Lucia, Australia
| | - Jane G Muir
- Department of Gastroenterology, Central Clinical School, The Alfred Centre, Monash University, Melbourne, Victoria, Australia
| | - Peter R Gibson
- Department of Gastroenterology, Central Clinical School, The Alfred Centre, Monash University, Melbourne, Victoria, Australia
| | - Páraic Ó Cuív
- The University of Queensland Diamantina Institute, Translational Research Institute, Brisbane, Queensland, Australia
| | - Philip Hugenholtz
- The University of Queensland Diamantina Institute, Translational Research Institute, Brisbane, Queensland, Australia.,Australian Centre for Ecogenomics, The University of Queensland, St Lucia, Australia.,School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
| | - Gene W Tyson
- Australian Centre for Ecogenomics, The University of Queensland, St Lucia, Australia.,School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
| | - Mark Morrison
- The University of Queensland Diamantina Institute, Translational Research Institute, Brisbane, Queensland, Australia. .,Australian Centre for Ecogenomics, The University of Queensland, St Lucia, Australia.
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Yan Z, Ferry JG. Electron Bifurcation and Confurcation in Methanogenesis and Reverse Methanogenesis. Front Microbiol 2018; 9:1322. [PMID: 29973922 PMCID: PMC6019823 DOI: 10.3389/fmicb.2018.01322] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 05/30/2018] [Indexed: 12/27/2022] Open
Abstract
Reduction of the disulfide of coenzyme M and coenzyme B (CoMS–SCoB) by heterodisulfide reductases (HdrED and HdrABC) is the final step in all methanogenic pathways. Flavin-based electron bifurcation (FBEB) by soluble HdrABC homologs play additional roles in driving essential endergonic reactions at the expense of the exergonic reduction of CoMS–SCoM. In the first step of the CO2 reduction pathway, HdrABC complexed with hydrogenase or formate dehydrogenase generates reduced ferredoxin (Fdx2-) for the endergonic reduction of CO2 coupled to the exergonic reduction of CoMS–SCoB dependent on FBEB of electrons from H2 or formate. Roles for HdrABC:hydrogenase complexes are also proposed for pathways wherein the methyl group of methanol is reduced to methane with electrons from H2. The HdrABC complexes catalyze FBEB-dependent oxidation of H2 for the endergonic reduction of Fdx driven by the exergonic reduction of CoMS–SCoB. The Fdx2- supplies electrons for reduction of the methyl group to methane. In H2- independent pathways, three-fourths of the methyl groups are oxidized producing Fdx2- and reduced coenzyme F420 (F420H2). The F420H2 donates electrons for reduction of the remaining methyl groups to methane requiring transfer of electrons from Fdx2- to F420. HdrA1B1C1 is proposed to catalyze FBEB-dependent oxidation of Fdx2- for the endergonic reduction of F420 driven by the exergonic reduction of CoMS–SCoB. In H2- independent acetotrophic pathways, the methyl group of acetate is reduced to methane with electrons derived from oxidation of the carbonyl group mediated by Fdx. Electron transport involves a membrane-bound complex (Rnf) that oxidizes Fdx2- and generates a Na+ gradient driving ATP synthesis. It is postulated that F420 is reduced by Rnf requiring HdrA2B2C2 catalyzing FBEB-dependent oxidation of F420H2 for the endergonic reduction of Fdx driven by the exergonic reduction of CoMS–SCoB. The Fdx2- is recycled by Rnf and HdrA2B2C2 thereby conserving energy. The HdrA2B2C2 is also proposed to play a role in Fe(III)-dependent reverse methanogenesis. A flavin-based electron confurcating (FBEC) HdrABC complex is proposed for nitrate-dependent reverse methanogenesis in which the oxidation of CoM-SH/CoB-SH and Fdx2- is coupled to reduction of F420. The F420H2 donates electrons to a membrane complex that generates a proton gradient driving ATP synthesis.
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Affiliation(s)
- Zhen Yan
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, State College, PA, United States
| | - James G Ferry
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, State College, PA, United States
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33
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Prakash D, Walters KA, Martinie RJ, McCarver AC, Kumar AK, Lessner DJ, Krebs C, Golbeck JH, Ferry JG. Toward a mechanistic and physiological understanding of a ferredoxin:disulfide reductase from the domains Archaea and Bacteria. J Biol Chem 2018; 293:9198-9209. [PMID: 29720404 DOI: 10.1074/jbc.ra118.002473] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 04/24/2018] [Indexed: 11/06/2022] Open
Abstract
Disulfide reductases reduce other proteins and are critically important for cellular redox signaling and homeostasis. Methanosarcina acetivorans is a methane-producing microbe from the domain Archaea that produces a ferredoxin:disulfide reductase (FDR) for which the crystal structure has been reported, yet its biochemical mechanism and physiological substrates are unknown. FDR and the extensively characterized plant-type ferredoxin:thioredoxin reductase (FTR) belong to a distinct class of disulfide reductases that contain a unique active-site [4Fe-4S] cluster. The results reported here support a mechanism for FDR similar to that reported for FTR with notable exceptions. Unlike FTR, FDR contains a rubredoxin [1Fe-0S] center postulated to mediate electron transfer from ferredoxin to the active-site [4Fe-4S] cluster. UV-visible, EPR, and Mössbauer spectroscopic data indicated that two-electron reduction of the active-site disulfide in FDR involves a one-electron-reduced [4Fe-4S]1+ intermediate previously hypothesized for FTR. Our results support a role for an active-site tyrosine in FDR that occupies the equivalent position of an essential histidine in the active site of FTR. Of note, one of seven Trxs encoded in the genome (Trx5) and methanoredoxin, a glutaredoxin-like enzyme from M. acetivorans, were reduced by FDR, advancing the physiological understanding of FDR's role in the redox metabolism of methanoarchaea. Finally, bioinformatics analyses show that FDR homologs are widespread in diverse microbes from the domain Bacteria.
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Affiliation(s)
- Divya Prakash
- From the Departments of Biochemistry and Molecular Biology and
| | - Karim A Walters
- From the Departments of Biochemistry and Molecular Biology and
| | - Ryan J Martinie
- Chemistry, Pennsylvania State University, University Park, Pennsylvania 16802 and
| | - Addison C McCarver
- the Department of Biological Sciences, University of Arkansas, Fayetteville, Arkansas 72701
| | - Adepu K Kumar
- From the Departments of Biochemistry and Molecular Biology and
| | - Daniel J Lessner
- the Department of Biological Sciences, University of Arkansas, Fayetteville, Arkansas 72701
| | - Carsten Krebs
- From the Departments of Biochemistry and Molecular Biology and.,Chemistry, Pennsylvania State University, University Park, Pennsylvania 16802 and
| | - John H Golbeck
- From the Departments of Biochemistry and Molecular Biology and.,Chemistry, Pennsylvania State University, University Park, Pennsylvania 16802 and
| | - James G Ferry
- From the Departments of Biochemistry and Molecular Biology and
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