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Zhang X, Zhao J, Erler DV, Rabiee H, Kong Z, Wang S, Wang Z, Virdis B, Yuan Z, Hu S. Characterization of the redox-active extracellular polymeric substances in an anaerobic methanotrophic consortium. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 365:121523. [PMID: 38901321 DOI: 10.1016/j.jenvman.2024.121523] [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: 03/12/2024] [Revised: 05/29/2024] [Accepted: 06/16/2024] [Indexed: 06/22/2024]
Abstract
Anaerobic oxidation of methane (AOM) is a microbial process of importance in the global carbon cycle. AOM is predominantly mediated by anaerobic methanotrophic archaea (ANME), the physiology of which is still poorly understood. Here we present a new addition to the current physiological understanding of ANME by examining, for the first time, the biochemical and redox-active properties of the extracellular polymeric substances (EPS) of an ANME enrichment culture. Using a 'Candidatus Methanoperedens nitroreducens'-dominated methanotrophic consortium as the representative, we found it can produce an EPS matrix featuring a high protein-to-polysaccharide ratio of ∼8. Characterization of EPS using FTIR revealed the dominance of protein-associated amide I and amide II bands in the EPS. XPS characterization revealed the functional group of C-(O/N) from proteins accounted for 63.7% of total carbon. Heme-reactive staining and spectroscopic characterization confirmed the distribution of c-type cytochromes in this protein-dominated EPS, which potentially enabled its electroactive characteristic. Redox-active c-type cytochromes in EPS mediated the EET of 'Ca. M. nitroreducens' for the reduction of Ag+ to metallic Ag, which was confirmed by both ex-situ experiments with extracted soluble EPS and in-situ experiments with pristine EPS matrix surrounding cells. The formation of nanoparticles in the EPS matrix during in-situ extracellular Ag + reduction resulted in a relatively lower intracellular Ag distribution fraction, beneficial for alleviating the Ag toxicity to cells. The results of this study provide the first biochemical information on EPS of anaerobic methanotrophic consortia and a new insight into its physiological role in AOM process.
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Affiliation(s)
- Xueqin Zhang
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, Brisbane, Queensland, Australia
| | - Jing Zhao
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, Brisbane, Queensland, Australia; Ecological Engineering of Mine Wastes, Sustainable Minerals Institute, The University of Queensland, Brisbane, Queensland, Australia
| | - Dirk V Erler
- Faculty of Science and Engineering, Southern Cross University, Lismore, NSW, Australia
| | - Hesamoddin Rabiee
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, Brisbane, Queensland, Australia; School of Chemical Engineering, The University of Queensland, Brisbane, Queensland, Australia; Centre for Future Materials, University of Southern Queensland, Springfield, Queensland, Australia
| | - Zheng Kong
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, Brisbane, Queensland, Australia
| | - Suicao Wang
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, Brisbane, Queensland, Australia
| | - Zhiyao Wang
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, Brisbane, Queensland, Australia
| | - Bernardino Virdis
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, Brisbane, Queensland, Australia
| | - Zhiguo Yuan
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, Brisbane, Queensland, Australia; School of Energy and Environment, City University of Hong Kong, Hong Kong SAR, China
| | - Shihu Hu
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, Brisbane, Queensland, Australia.
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He Z, Shen J, Zhu Y, Gao J, Zhang D, Pan X. Active anaerobic methane oxidation in the groundwater table fluctuation zone of rice paddies. WATER RESEARCH 2024; 258:121802. [PMID: 38796914 DOI: 10.1016/j.watres.2024.121802] [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: 02/19/2024] [Revised: 04/30/2024] [Accepted: 05/18/2024] [Indexed: 05/29/2024]
Abstract
Rice paddies are globally important sources of methane emissions and also active regions for methane consumption. However, the impact of fluctuating groundwater levels on methane cycling has received limited attention. In this study, we delved into the activity and microbial mechanisms underlying anaerobic oxidation of methane (AOM) in paddy fields. A comprehensive approach was employed, including 13C stable isotope assays, inhibition experiments, real-time quantitative reverse transcription PCR, metagenomic sequencing, and binning technology. Geochemical profiles revealed the abundant coexistence of both methane and electron acceptors in the groundwater table fluctuation (GTF) zone, at a depth of 40-60 cm. Notably, the GTF zone exhibited the highest rate of AOM, potentially linked to the reduction of iron oxides and nitrate. Within this zone, Candidatus Methanoperedens (belonging to the ANME-2d group) dominated the Archaea population, accounting for a remarkable 85.4 %. Furthermore, our results from inhibition experiments, RT-qPCR, and metagenome-assembled genome (MAG) analysis highlighted the active role of Ca. Methanoperedens GTF50 in the GTF zone. This microorganism could independently mediate AOM process through the intriguing "reverse methanogenesis" pathway. Considering the similarity in geochemical conditions across different paddy fields, it is likely that Ca. Methanoperedens-mediated AOM is prevalent in the GTF zones.
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Affiliation(s)
- Zhanfei He
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Jiaquan Shen
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Yinghong Zhu
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Jingxun Gao
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Daoyong Zhang
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Xiangliang Pan
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou 310014, China.
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Li R, Xi B, Wang X, Li Y, Yuan Y, Tan W. Anaerobic oxidation of methane in landfill and adjacent groundwater environments: Occurrence, mechanisms, and potential applications. WATER RESEARCH 2024; 255:121498. [PMID: 38522398 DOI: 10.1016/j.watres.2024.121498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 02/08/2024] [Accepted: 03/19/2024] [Indexed: 03/26/2024]
Abstract
Landfills remain the predominant means of solid waste management worldwide. Widespread distribution and significant stockpiles of waste in landfills make them a significant source of methane emissions, exacerbating climate change. Anaerobic oxidation of methane (AOM) has been shown to play a critical role in mitigating methane emissions on a global scale. The rich methane and electron acceptor environment in landfills provide the necessary reaction conditions for AOM, making it a potentially low-cost and effective strategy for reducing methane emissions in landfills. However, compared to other anaerobic habitats, research on AOM in landfill environments is scarce, and there is a lack of analysis on the potential application of AOM in different zones of landfills. Therefore, this review summarizes the existing knowledge on AOM and its occurrence in landfills, analyzes the possibility of AOM occurrence in different zones of landfills, discusses its potential applications, and explores the challenges and future research directions for AOM in landfill management. The identification of research gaps and future directions outlined in this review encourages further investigation and advancement in the field of AOM, paving the way for more effective waste stabilization, greenhouse gas reduction, and pollutant mitigation strategies in landfills.
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Affiliation(s)
- Renfei Li
- State Key Laboratory of Environmental Criteria and Risk Assessment, and State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, PR China; School of Environment, Tsinghua University, Beijing 100084, PR China
| | - Beidou Xi
- State Key Laboratory of Environmental Criteria and Risk Assessment, and State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, PR China; School of Environment, Tsinghua University, Beijing 100084, PR China.
| | - Xiaowei Wang
- Department of Environmental Science and Engineering, Beijing Technology and Business University, Beijing 100048, PR China
| | - Yanjiao Li
- State Key Laboratory of Environmental Criteria and Risk Assessment, and State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, PR China
| | - Ying Yuan
- State Key Laboratory of Environmental Criteria and Risk Assessment, and State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, PR China
| | - Wenbing Tan
- State Key Laboratory of Environmental Criteria and Risk Assessment, and State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, PR China
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Xie M, Zhang X, Li S, Maulani N, Cai F, Zheng Y, Cai C, Virdis B, Yuan Z, Hu S. Humic substances as electron acceptor for anaerobic oxidation of methane (AOM) and electron shuttle in Mn (IV)-dependent AOM. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:169576. [PMID: 38145665 DOI: 10.1016/j.scitotenv.2023.169576] [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: 09/05/2023] [Revised: 12/19/2023] [Accepted: 12/19/2023] [Indexed: 12/27/2023]
Abstract
Anaerobic methanotrophic archaea (ANME) belonging to the family Methanoperedenaceae are crucial for the global carbon cycle and different biogeochemical processes, owing to their metabolic versatility to couple anaerobic oxidation of methane (AOM) with different electron acceptors. A universal feature of Methanoperedenaceae is the abundant genes encoded in their genomes associated with extracellular electron transfer (EET) pathways. Candidatus. 'Methanoperedens manganicus', an archaeon belonging to the family Methanoperedenaceae, was recently enriched in a bioreactor performing AOM coupled with Mn (IV) reduction. Using this EET-capable ANME, we tested the hypothesis in this study that ANME can catalyse the humic-dependent AOM for growth. A two-year incubation showed that AOM activity can be sustained by Ca. 'M. manganicus' consortium in a bioreactor fed only with humic acids and methane. An isotopic mass balance batch test confirmed that the observed AOM was coupled to the reduction of humic acids. The increase of relative abundance of Ca. 'M. manganicus', and the total archaea population in the microbial community suggested that Ca. 'M. manganicus' can grow on methane and humic acids. The observation of humic-dependent AOM led to a subsequent hypothesis that humic acids could be used as the electron shuttle to mediate the EET in dissimilatory Mn (IV) reduction by Ca. 'M. manganicus'. We tested this hypothesis by adding humic acids to a Ca. 'M. manganicus' dominated-culture, which showed that the AOM rate was doubled by the addition of humic acids. X-ray photoelectron spectroscopy (XPS) showed that quinone moieties were consumed when humic acids worked as electron acceptors while remaining stable when functioning as a shuttle for electron transfer. The results of our study suggest that humic acids may serve as electron shuttles to allow ANME to access more electron acceptors through long-range EET.
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Affiliation(s)
- Mengying Xie
- Australian Centre for Water and Environmental Biotechnology, Faculty of Engineering, Architecture and Information Technology, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Xueqin Zhang
- Australian Centre for Water and Environmental Biotechnology, Faculty of Engineering, Architecture and Information Technology, The University of Queensland, St. Lucia, Queensland 4072, Australia.
| | - Shiqing Li
- Australian Centre for Water and Environmental Biotechnology, Faculty of Engineering, Architecture and Information Technology, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Nova Maulani
- Australian Centre for Water and Environmental Biotechnology, Faculty of Engineering, Architecture and Information Technology, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Fangrui Cai
- Australian Centre for Water and Environmental Biotechnology, Faculty of Engineering, Architecture and Information Technology, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Yue Zheng
- State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Xiamen University, Xiamen 361102, China
| | - Chen Cai
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Bernardino Virdis
- Australian Centre for Water and Environmental Biotechnology, Faculty of Engineering, Architecture and Information Technology, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Zhiguo Yuan
- School of Energy and Environment, City University of Hong Kong, Kowloon, Hong Kong 999077, China
| | - Shihu Hu
- Australian Centre for Water and Environmental Biotechnology, Faculty of Engineering, Architecture and Information Technology, The University of Queensland, St. Lucia, Queensland 4072, Australia
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5
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Zhang X, Xie M, Cai C, Rabiee H, Wang Z, Virdis B, Tyson GW, McIlroy SJ, Yuan Z, Hu S. Pyrogenic Carbon Promotes Anaerobic Oxidation of Methane Coupled with Iron Reduction via the Redox-Cycling Mechanism. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:19793-19804. [PMID: 37947777 DOI: 10.1021/acs.est.3c05907] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2023]
Abstract
Pyrogenic carbon (PC) can mediate electron transfer and thus catalyze biogeochemical processes to impact greenhouse gas (GHG) emissions. Here, we demonstrate that PC can contribute to mitigating GHG emissions by promoting the Fe(III)-dependent anaerobic oxidation of methane (AOM). It was found that the amendment PCs in microcosms dominated by Methanoperedenaceae performing Fe(III)-dependent AOM simultaneously promoted the rate of AOM and Fe(III) reduction with a consistent ratio close to the theoretical stoichiometry of 1:8. Further correlation analysis showed that the AOM rate was linearly correlated with the electron exchange capacity, but not the conductivity, of added PC materials, indicating the redox-cycling electron transfer mechanism to promote the Fe(III)-dependent AOM. The mass content of the C═O moiety from differentially treated PCs was well correlated with the AOM rate, suggesting that surface redox-active quinone groups on PCs contribute to facilitating Fe(III)-dependent AOM. Further microbial analyses indicate that PC likely shuttles direct electron transfer from Methanoperedenaceae to Fe(III) reduction. This study provides new insight into the climate-cooling impact of PCs, and our evaluation indicates that the PC-facilitated Fe(III)-dependent AOM could have a significant contribution to suppressing methane emissions from the world's reservoirs.
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Affiliation(s)
- Xueqin Zhang
- Australian Centre for Water and Environmental Biotechnology (ACWEB), Faculty of Engineering, Architecture and Information Technology, University of Queensland, Brisbane, Queensland 4067, Australia
| | - Mengying Xie
- Australian Centre for Water and Environmental Biotechnology (ACWEB), Faculty of Engineering, Architecture and Information Technology, University of Queensland, Brisbane, Queensland 4067, Australia
| | - Chen Cai
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
| | - Hesamoddin Rabiee
- Australian Centre for Water and Environmental Biotechnology (ACWEB), Faculty of Engineering, Architecture and Information Technology, University of Queensland, Brisbane, Queensland 4067, Australia
- School of Chemical Engineering, The University of Queensland, Brisbane, Queensland 4072, Australia
- Centre for Future Materials, University of Southern Queensland, Springfield, Queensland 4300, Australia
| | - Zhiyao Wang
- Australian Centre for Water and Environmental Biotechnology (ACWEB), Faculty of Engineering, Architecture and Information Technology, University of Queensland, Brisbane, Queensland 4067, Australia
| | - Bernardino Virdis
- Australian Centre for Water and Environmental Biotechnology (ACWEB), Faculty of Engineering, Architecture and Information Technology, University of Queensland, Brisbane, Queensland 4067, Australia
| | - Gene W Tyson
- Centre for Microbiome Research, School of Biomedical Sciences, Translational Research Institute, Queensland University of Technology (QUT), Woolloongabba Queensland 4001, Australia
| | - Simon J McIlroy
- Centre for Microbiome Research, School of Biomedical Sciences, Translational Research Institute, Queensland University of Technology (QUT), Woolloongabba Queensland 4001, Australia
| | - Zhiguo Yuan
- School of Energy and Environment, City University of Hong Kong, Hong Kong, SAR, China
| | - Shihu Hu
- Australian Centre for Water and Environmental Biotechnology (ACWEB), Faculty of Engineering, Architecture and Information Technology, University of Queensland, Brisbane, Queensland 4067, Australia
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6
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Zhao Q, Lu Y. Anaerobic oxidation of methane in terrestrial wetlands: The rate, identity and metabolism. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 902:166049. [PMID: 37543312 DOI: 10.1016/j.scitotenv.2023.166049] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 07/19/2023] [Accepted: 08/02/2023] [Indexed: 08/07/2023]
Abstract
The recent discovery of anaerobic oxidation of methane (AOM) in freshwater ecosystems has caused a great interest in "cryptic methane cycle" in terrestrial ecosystems. Anaerobic methanotrophs appears widespread in wetland ecosystems, yet, the scope and mechanism of AOM in natural wetlands remain poorly understood. In this paper, we review the recent progress regarding the potential of AOM, the diversity and distribution, and the metabolism of anaerobic methanotrophs in wetland ecosystems. The potential of AOM determined through laboratory incubation or in situ isotopic labeling ranges from 1.4 to 704.0 nmol CH4·g-1 dry soil·d-1. It appears that the availability of electron acceptors is critical in driving different AOM in wetland soils. The environmental temperature and salinity exert a significant influence on AOM activity. Reversal methanogenesis and extracellular electron transfer are likely involved in the AOM process. In addition to anaerobic methanotrophic archaea, the direct involvement of methanogens in AOM is also probable. This review presented an overview of the rate, identity, and metabolisms to unravel the biogeochemical puzzle of AOM in wetland soils.
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Affiliation(s)
- Qingzhou Zhao
- College of Urban and Environmental Science, Peking University, Beijing 100871, PR China
| | - Yahai Lu
- College of Urban and Environmental Science, Peking University, Beijing 100871, PR China.
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Zhang X, Joyce GH, Leu AO, Zhao J, Rabiee H, Virdis B, Tyson GW, Yuan Z, McIlroy SJ, Hu S. Multi-heme cytochrome-mediated extracellular electron transfer by the anaerobic methanotroph 'Candidatus Methanoperedens nitroreducens'. Nat Commun 2023; 14:6118. [PMID: 37777538 PMCID: PMC10542353 DOI: 10.1038/s41467-023-41847-w] [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: 06/08/2023] [Accepted: 09/18/2023] [Indexed: 10/02/2023] Open
Abstract
Anaerobic methanotrophic archaea (ANME) carry out anaerobic oxidation of methane, thus playing a crucial role in the methane cycle. Previous genomic evidence indicates that multi-heme c-type cytochromes (MHCs) may facilitate the extracellular electron transfer (EET) from ANME to different electron sinks. Here, we provide experimental evidence supporting cytochrome-mediated EET for the reduction of metals and electrodes by 'Candidatus Methanoperedens nitroreducens', an ANME acclimated to nitrate reduction. Ferrous iron-targeted fluorescent assays, metatranscriptomics, and single-cell imaging suggest that 'Ca. M. nitroreducens' uses surface-localized redox-active cytochromes for metal reduction. Electrochemical and Raman spectroscopic analyses also support the involvement of c-type cytochrome-mediated EET for electrode reduction. Furthermore, several genes encoding menaquinone cytochrome type-c oxidoreductases and extracellular MHCs are differentially expressed when different electron acceptors are used.
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Affiliation(s)
- Xueqin Zhang
- Australian Centre for Water and Environmental Biotechnology (ACWEB), Faculty of Engineering, Architecture and Information Technology, University of Queensland, Brisbane, Australia
| | - Georgina H Joyce
- Centre for Microbiome Research, School of Biomedical Sciences, Queensland University of Technology (QUT), Translational Research Institute, Woolloongabba, Australia
| | - Andy O Leu
- Centre for Microbiome Research, School of Biomedical Sciences, Queensland University of Technology (QUT), Translational Research Institute, Woolloongabba, Australia
| | - Jing Zhao
- Australian Centre for Water and Environmental Biotechnology (ACWEB), Faculty of Engineering, Architecture and Information Technology, University of Queensland, Brisbane, Australia
- Ecological Engineering of Mine Wastes, Sustainable Minerals Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Hesamoddin Rabiee
- Australian Centre for Water and Environmental Biotechnology (ACWEB), Faculty of Engineering, Architecture and Information Technology, University of Queensland, Brisbane, Australia
- School of Chemical Engineering, The University of Queensland, Brisbane, QLD, Australia
- Centre for Future Materials, University of Southern Queensland, Springfield, QLD, Australia
| | - Bernardino Virdis
- Australian Centre for Water and Environmental Biotechnology (ACWEB), Faculty of Engineering, Architecture and Information Technology, University of Queensland, Brisbane, Australia
| | - Gene W Tyson
- Centre for Microbiome Research, School of Biomedical Sciences, Queensland University of Technology (QUT), Translational Research Institute, Woolloongabba, Australia
| | - Zhiguo Yuan
- Australian Centre for Water and Environmental Biotechnology (ACWEB), Faculty of Engineering, Architecture and Information Technology, University of Queensland, Brisbane, Australia
- School of Energy and Environment, City University of Hong Kong, Hong Kong SAR, China
| | - Simon J McIlroy
- Centre for Microbiome Research, School of Biomedical Sciences, Queensland University of Technology (QUT), Translational Research Institute, Woolloongabba, Australia
| | - Shihu Hu
- Australian Centre for Water and Environmental Biotechnology (ACWEB), Faculty of Engineering, Architecture and Information Technology, University of Queensland, Brisbane, Australia.
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Frank J, Zhang X, Marcellin E, Yuan Z, Hu S. Salinity effect on an anaerobic methane- and ammonium-oxidising consortium: Shifts in activity, morphology, osmoregulation and syntrophic relationship. WATER RESEARCH 2023; 242:120090. [PMID: 37331229 DOI: 10.1016/j.watres.2023.120090] [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: 03/02/2023] [Revised: 05/04/2023] [Accepted: 05/16/2023] [Indexed: 06/20/2023]
Abstract
Nitrate-dependent anaerobic methane oxidation (AOM) is a microbial process of both ecological significance for global methane mitigation and application potential for wastewater treatment. It is mediated by organisms belonging to the archaeal family 'Candidatus Methanoperedenaceae', which have so far mainly been found in freshwater environments. Their potential distribution in saline environments and their physiological responses to salinity variation were still poorly understood. In this study, the responses of the freshwater 'Candidatus Methanoperedens nitroreducens'-dominated consortium to different salinities were investigated using short- and long-term setups. Short-term exposure to salt stress significantly affected nitrate reduction and methane oxidation activities over the tested concentration range of 15-200‰ NaCl, and 'Ca. M. nitroreducens' showed the higher tolerance to high salinity stress than its partner of anammox bacteria. At high salinity concentration, near marine conditions of 37‰, the target organism 'Ca. M. nitroreducens' showed stabilized nitrate reduction activity of 208.5 µmol day-1 gCDW-1 in long-term bioreactors over 300 days, in comparison to 362.9 and 334.3 µmol day-1 gCDW-1 under low-salinity conditions (1.7‰ NaCl) and control conditions (∼15‰ NaCl). Different partners of 'Ca. M. nitroreducens' evolved in the consortia with three different salinity conditions, suggesting the different syntrophic mechanisms shaped by changes in salinity. A new syntrophic relationship between 'Ca. M. nitroreducens' and Fimicutes and/or Chloroflexi denitrifying populations was identified under the marine salinity condition. Metaproteomic analysis shows that the salinity changes lead to higher expression of response regulators and selective ion (Na+/H+) channeling proteins that can regulate the osmotic pressure between the cell and its environment. The reverse methanogenesis pathway was, however, not impacted. The finding of this study has important implications for the ecological distribution of the nitrate-dependent AOM process in marine environments and the potential of this biotechnological process for the treatment of high-salinity industrial wastewater.
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Affiliation(s)
- Joshua Frank
- Australian Centre for Water and Environmental Biotechnology (ACWEB), Faculty of Engineering, Architecture and Information Technology, The University of Queensland, St Lucia, Brisbane, QLD 4072, Australia
| | - Xueqin Zhang
- Australian Centre for Water and Environmental Biotechnology (ACWEB), Faculty of Engineering, Architecture and Information Technology, The University of Queensland, St Lucia, Brisbane, QLD 4072, Australia.
| | - Esteban Marcellin
- Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
| | - Zhiguo Yuan
- Australian Centre for Water and Environmental Biotechnology (ACWEB), Faculty of Engineering, Architecture and Information Technology, The University of Queensland, St Lucia, Brisbane, QLD 4072, Australia
| | - Shihu Hu
- Australian Centre for Water and Environmental Biotechnology (ACWEB), Faculty of Engineering, Architecture and Information Technology, The University of Queensland, St Lucia, Brisbane, QLD 4072, Australia.
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9
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Chai F, Li L, Wang W, Xue S, Liu J. Electro-stimulated anaerobic oxidation of methane with synergistic denitrification by adding AQS: Electron transfer mode and mechanism. ENVIRONMENTAL RESEARCH 2023; 229:115997. [PMID: 37105293 DOI: 10.1016/j.envres.2023.115997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Revised: 04/10/2023] [Accepted: 04/24/2023] [Indexed: 05/21/2023]
Abstract
Denitrifying anaerobic methane-oxidizing (DAMO) processes, which link anaerobic methane oxidation (AMO) and denitrification, have a promising prospect in anaerobic wastewater treatment. In bioelectrochemical systems (BES), DAMO consortium presented potent metabolic activity. However, the extracellular electron transfer (EET) in BES was poorly understood. This study investigated the EET mechanisms and modes of electron transport in BES dominated by anaerobic methanotrophic bacteria. In the bioreactors with the auxiliary voltage of 0.5 and 1.1 V, named EMN-0.5 and EMN-1.1, respectively, biological voltages of 0.198 and 0.329 V were generated with power densities of 0.6 and 1.20 mW/m2, after removing the voltage. High throughput and metagenome analyses demonstrated that main methanotrophs were DAMO bacteria and Methylocystis sp. The electroactive bacteria detected were Pseudomonas sp., Hypomicrobium sp., Thiobacillus sp, and Rhodococcus sp. The pil, cytochrome c, hdr, and he/fp genes related to EET were present on the electrode surfaces. Carbon 13 isotope tracing and chemicals analysis by GC-MS exhibited that methanol was an intermediate product released to extracellular environment and acted as the electronic carrier to drive the EET in methane oxidation. Extracellular electron transfer was achieved through the collaboration of DAMO bacteria, Methylocystis sp., and Pseudomonas sp. Anthraquinone 2-sulfonic acid ester (AQS) could improve the rate of electron transfer to the extracellular space, especially in the EMN-0.5 reaction system. This study provides a new understanding of AMO consortium metabolism in BES and may provide a scientific basis for developing methane control technology.
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Affiliation(s)
- Fengguang Chai
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Haidian District, Beijing, 100085, China; School of Ecology and Environment, Zhengzhou University, Zhengzhou, 450001, China
| | - Lin Li
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Haidian District, Beijing, 100085, China; National Engineering Laboratory for VOCs Pollution Control Material & Technology, University of Chinese Academy of Sciences, Beijing, 101408, China.
| | - Wenwen Wang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Haidian District, Beijing, 100085, China; University of Chinese Academy of Sciences, 19(A) Yuquan Road, Shijingshan District, Beijing, 100049, China
| | - Song Xue
- Environmental Simulation and Pollution Control State Key Joint Laboratory, State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC), School of Environment, Tsinghua University, Beijing, 100084, PR China
| | - Junxin Liu
- University of Chinese Academy of Sciences, 19(A) Yuquan Road, Shijingshan District, Beijing, 100049, China
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10
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Guo X, Lai CY, Hartmann EM, Zhao HP. Heterotrophic denitrification: An overlooked factor that contributes to nitrogen removal in n-DAMO mixed culture. ENVIRONMENTAL RESEARCH 2023; 216:114802. [PMID: 36375502 DOI: 10.1016/j.envres.2022.114802] [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: 10/10/2022] [Revised: 11/05/2022] [Accepted: 11/10/2022] [Indexed: 06/16/2023]
Abstract
Nitrate/nitrite-dependent anaerobic methane oxidation (n-DAMO) has been recognized as a sustainable process for simultaneous removal of nitrogen and methane. The metabolisms of denitrifying anaerobic methanotrophs, including Candidatus Methanoperedens and Candidatus Methylomirabilis, have been well studied. However, potential roles of heterotrophs co-existing with these anaerobic methanotrophs are generally overlooked. In this study, we pulse-fed methane and nitrate into an anaerobic laboratory sequencing batch bioreactor and enriched a mixed culture with stable nitrate removal rate (NRR) of ∼28 mg NO3--N L-1 d-1. Microbial community analysis indicates abundant heterotrophs, e.g., Arenimonas (5.3%-18.9%) and Fimbriimonadales ATM1 (6.4%), were enriched together with denitrifying anaerobic methanotrophs Ca. Methanoperedens (10.8%-13.2%) and Ca. Methylomirabilis (27.4%-34.3%). The results of metagenomics and batch tests suggested that the denitrifying anaerobic methanotrophs were capable of generating methane-derived intermediates (i.e., formate and acetate), which were employed by non-methanotrophic heterotrophs for denitrification and biomass growth. These findings offer new insights into the roles of heterotrophs in n-DAMO mixed culture, which may help to optimize n-DAMO process for nitrogen removal from wastewater.
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Affiliation(s)
- Xu Guo
- MOE Key Lab of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Science, Zhejiang University, Hangzhou, 310058, China
| | - Chun-Yu Lai
- MOE Key Lab of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Science, Zhejiang University, Hangzhou, 310058, China
| | - Erica M Hartmann
- Department of Civil and Environmental Engineering, Northwestern University, IL, 60208, USA
| | - He-Ping Zhao
- MOE Key Lab of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Science, Zhejiang University, Hangzhou, 310058, China.
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11
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Guberman-Pfeffer MJ. Assessing Thermal Response of Redox Conduction for Anti-Arrhenius Kinetics in a Microbial Cytochrome Nanowire. J Phys Chem B 2022; 126:10083-10097. [PMID: 36417757 PMCID: PMC9743091 DOI: 10.1021/acs.jpcb.2c06822] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
A micrometers-long helical homopolymer of the outer-membrane cytochrome type S (OmcS) from Geobacter sulfurreducens is proposed to transport electrons to extracellular acceptors in an ancient respiratory strategy of biogeochemical and technological significance. OmcS surprisingly exhibits higher conductivity upon cooling (anti-Arrhenius kinetics), an effect previously attributed to H-bond restructuring and heme redox potential shifts. Herein, the temperature sensitivity of redox conductivity is more thoroughly examined with conventional and constant-redox and -pH molecular dynamics and quantum mechanics/molecular mechanics. A 30 K drop in temperature constituted a weak perturbation to electron transfer energetics, changing electronic couplings (⟨Hmn⟩), reaction free energies (ΔGmn), reorganization energies (λmn), and activation energies (Ea) by at most |0.002|, |0.050|, |0.120|, and |0.045| eV, respectively. Changes in ΔGmn reflected -0.07 ± 0.03 V shifts in redox potentials that were caused in roughly equal measure by altered electrostatic interactions with the solvent and protein. Changes in intraprotein H-bonding reproduced the earlier observations. Single-particle diffusion and multiparticle steady-state flux models, parametrized with Marcus theory rates, showed that biologically relevant incoherent hopping cannot qualitatively or quantitatively describe electrical conductivity measured by atomic force microscopy in filamentous OmcS. The discrepancy is attributed to differences between solution-phase simulations and solid-state measurements and the need to model intra- and intermolecular vibrations explicitly.
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Affiliation(s)
- Matthew J. Guberman-Pfeffer
- Department
of Molecular Biophysics and Biochemistry, Yale University, 333 Cedar St., New Haven, Connecticut06510, United States,Microbial
Sciences Institute, Yale University, 840 West Campus Drive, West Haven, Connecticut06516, United States,
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12
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Cervantes FJ, Ramírez-Montoya LA. Immobilized Nanomaterials for Environmental Applications. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27196659. [PMID: 36235196 PMCID: PMC9572314 DOI: 10.3390/molecules27196659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 09/27/2022] [Accepted: 10/05/2022] [Indexed: 11/16/2022]
Abstract
Nanomaterials (NMs) have been extensively used in several environmental applications; however, their widespread dissemination at full scale is hindered by difficulties keeping them active in engineered systems. Thus, several strategies to immobilize NMs for their environmental utilization have been established and are described in the present review, emphasizing their role in the production of renewable energies, the removal of priority pollutants, as well as greenhouse gases, from industrial streams, by both biological and physicochemical processes. The challenges to optimize the application of immobilized NMs and the relevant research topics to consider in future research are also presented to encourage the scientific community to respond to current needs.
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13
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Zhang X, McIlroy SJ, Vassilev I, Rabiee H, Plan M, Cai C, Virdis B, Tyson GW, Yuan Z, Hu S. Polyhydroxyalkanoate-driven current generation via acetate by an anaerobic methanotrophic consortium. WATER RESEARCH 2022; 221:118743. [PMID: 35724480 DOI: 10.1016/j.watres.2022.118743] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 05/23/2022] [Accepted: 06/11/2022] [Indexed: 06/15/2023]
Abstract
Anaerobic oxidation of methane (AOM) is an important microbial process mitigating methane (CH4) emission from natural sediments. Anaerobic methanotrophic archaea (ANME) have been shown to mediate AOM coupled to the reduction of several compounds, either directly (i.e. nitrate, metal oxides) or in consortia with syntrophic bacterial partners (i.e. sulfate). However, the mechanisms underlying extracellular electron transfer (EET) between ANME and their bacterial partners or external electron acceptors are poorly understood. In this study, we investigated electron and carbon flow for an anaerobic methanotrophic consortium dominated by 'Candidatus Methanoperedens nitroreducens' in a CH4-fed microbial electrolysis cell (MEC). Acetate was identified as a likely intermediate for the methanotrophic consortium, which stimulated the growth of the known electroactive genus Geobacter. Electrochemical characterization, stoichiometric calculations of the system, along with stable isotope-based assays, revealed that acetate was not produced from CH4 directly. In the absence of CH4, current was still generated and the microbial community remained largely unchanged. A substantial portion of the generated current in the absence of CH4 was linked to the oxidation of the intracellular polyhydroxybutyrate (PHB) and the breakdown of extracellular polymeric substances (EPSs). The ability of 'Ca. M. nitroreducens' to use stored PHB as a carbon and energy source, and its ability to donate acetate as a diffusible electron carrier expands the known metabolic diversity of this lineage that likely underpins its success in natural systems.
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Affiliation(s)
- Xueqin Zhang
- Australian Centre for Water and Environmental Biotechnology (ACWEB, formerly AWMC), The University of Queensland, Brisbane 4072, Australia.
| | - Simon J McIlroy
- Centre for Microbiome Research, School of Biomedical Sciences, Queensland University of Technology (QUT), Translational Research Institute, Woolloongabba, Australia
| | - Igor Vassilev
- Faculty of Engineering and Natural Sciences, Tampere University, Tampere, Finland
| | - Hesamoddin Rabiee
- Australian Centre for Water and Environmental Biotechnology (ACWEB, formerly AWMC), The University of Queensland, Brisbane 4072, Australia
| | - Manuel Plan
- Metabolomics Australia (Queensland Node), Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Chen Cai
- Australian Centre for Water and Environmental Biotechnology (ACWEB, formerly AWMC), The University of Queensland, Brisbane 4072, Australia; CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
| | - Bernardino Virdis
- Australian Centre for Water and Environmental Biotechnology (ACWEB, formerly AWMC), The University of Queensland, Brisbane 4072, Australia
| | - Gene W Tyson
- Centre for Microbiome Research, School of Biomedical Sciences, Queensland University of Technology (QUT), Translational Research Institute, Woolloongabba, Australia
| | - Zhiguo Yuan
- Australian Centre for Water and Environmental Biotechnology (ACWEB, formerly AWMC), The University of Queensland, Brisbane 4072, Australia
| | - Shihu Hu
- Australian Centre for Water and Environmental Biotechnology (ACWEB, formerly AWMC), The University of Queensland, Brisbane 4072, Australia.
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