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Zhao Y, Liu Y, Cao S, Hao Q, Liu C, Li Y. Anaerobic oxidation of methane driven by different electron acceptors: A review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 946:174287. [PMID: 38945238 DOI: 10.1016/j.scitotenv.2024.174287] [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: 02/06/2024] [Revised: 05/31/2024] [Accepted: 06/23/2024] [Indexed: 07/02/2024]
Abstract
Methane, the most significant reduced form of carbon on Earth, acts as a crucial fuel and greenhouse gas. Globally, microbial methane sinks encompass both aerobic oxidation of methane (AeOM), conducted by oxygen-utilizing methanotrophs, and anaerobic oxidation of methane (AOM), performed by anaerobic methanotrophs employing various alternative electron acceptors. These electron acceptors involved in AOM include sulfate, nitrate/nitrite, humic substances, and diverse metal oxides. The known anaerobic methanotrophic pathways comprise the internal aerobic oxidation pathway found in NC10 bacteria and the reverse methanogenesis pathway utilized by anaerobic methanotrophic archaea (ANME). Diverse anaerobic methanotrophs can perform AOM independently or in cooperation with symbiotic partners through several extracellular electron transfer (EET) pathways. AOM has been documented in various environments, including seafloor methane seepages, coastal wetlands, freshwater lakes, soils, and even extreme environments like hydrothermal vents. The environmental activities of AOM processes, driven by different electron acceptors, primarily depend on the energy yields, availability of electron acceptors, and environmental adaptability of methanotrophs. It has been suggested that different electron acceptors driving AOM may occur across a wider range of habitats than previously recognized. Additionally, it is proposed that methanotrophs have evolved flexible metabolic strategies to adapt to complex environmental conditions. This review primarily focuses on AOM, driven by different electron acceptors, discussing the associated reaction mechanisms and the habitats where these processes are active. Furthermore, it emphasizes the pivotal role of AOM in mitigating methane emissions.
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Affiliation(s)
- Yuewen Zhao
- Fujian Provincial Key Laboratory of Water Cycling and Eco-Geological Processes, Xiamen 361021, China; Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang 050061, China
| | - Yaci Liu
- Fujian Provincial Key Laboratory of Water Cycling and Eco-Geological Processes, Xiamen 361021, China; Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang 050061, China.
| | - Shengwei Cao
- Fujian Provincial Key Laboratory of Water Cycling and Eco-Geological Processes, Xiamen 361021, China; Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang 050061, China
| | - Qichen Hao
- Fujian Provincial Key Laboratory of Water Cycling and Eco-Geological Processes, Xiamen 361021, China; Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang 050061, China
| | - Chunlei Liu
- Fujian Provincial Key Laboratory of Water Cycling and Eco-Geological Processes, Xiamen 361021, China; Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang 050061, China
| | - Yasong Li
- Fujian Provincial Key Laboratory of Water Cycling and Eco-Geological Processes, Xiamen 361021, China; Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang 050061, China.
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Zuo Q, Yang Y, Xie X, Yang L, Zhang Q, He X. Grinding siderite with ferric sulfate to generate an active ferrous source for Cr(VI) reduction. CHEMOSPHERE 2024; 361:142516. [PMID: 38850691 DOI: 10.1016/j.chemosphere.2024.142516] [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: 02/06/2024] [Revised: 05/12/2024] [Accepted: 05/31/2024] [Indexed: 06/10/2024]
Abstract
Activated siderite, endowed with excellent properties, was simply prepared by co-grinding with Fe sulfate to enhance its high reducing ability for Cr(VI). Batch experiments were conducted to investigate the main affecting parameters, such as material ratio, pH, temperature, etc. The removal of Cr(VI) by activated siderite was completed within 4 h of the reaction. The activated siderite maintained a high removal effect of Cr(VI) within a wide pH range (3-9). Various analytical methods, including XRD, SEM/EDS, XPS, etc., were employed to characterize the samples and discover variations before and after the reaction. The Fe (Ⅱ) in activated siderite becomes highly active, and it can even be released from the solid phase in the mildly acidic liquid phase to efficiently reduce Cr(VI) and mitigate its toxicity. These findings introduce an innovative approach for activating various minerals widely distributed in nature to promote the recovery of the ecological system.
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Affiliation(s)
- Qiang Zuo
- Hubei Key Laboratory of Mineral Resources Processing and Environment, School of Resources and Environmental Engineering, Wuhan University of Technology, Wuhan, 430070, China
| | - Yi Yang
- Hubei Key Laboratory of Mineral Resources Processing and Environment, School of Resources and Environmental Engineering, Wuhan University of Technology, Wuhan, 430070, China
| | - Xin Xie
- Hubei Key Laboratory of Mineral Resources Processing and Environment, School of Resources and Environmental Engineering, Wuhan University of Technology, Wuhan, 430070, China
| | - Lie Yang
- Hubei Key Laboratory of Mineral Resources Processing and Environment, School of Resources and Environmental Engineering, Wuhan University of Technology, Wuhan, 430070, China
| | - Qiwu Zhang
- Hubei Key Laboratory of Mineral Resources Processing and Environment, School of Resources and Environmental Engineering, Wuhan University of Technology, Wuhan, 430070, China
| | - Xiaoman He
- Hubei Key Laboratory of Mineral Resources Processing and Environment, School of Resources and Environmental Engineering, Wuhan University of Technology, Wuhan, 430070, China.
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Tan X, Lu Y, Nie WB, Evans P, Wang XW, Dang CC, Wang X, Liu BF, Xing DF, Ren NQ, Xie GJ. Nitrate-dependent anaerobic methane oxidation coupled to Fe(III) reduction as a source of ammonium and nitrous oxide. WATER RESEARCH 2024; 256:121571. [PMID: 38583332 DOI: 10.1016/j.watres.2024.121571] [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: 02/01/2024] [Revised: 03/31/2024] [Accepted: 04/02/2024] [Indexed: 04/09/2024]
Abstract
'Candidatus Methanoperedens nitroreducens' is an archaeal methanotroph with global importance that links carbon and nitrogen cycles and great potential for sustainable operation of wastewater treatment. It has been reported to mediate the anaerobic oxidation of methane through a reverse methanogenesis pathway while reducing nitrate to nitrite. Here, we demonstrate that 'Ca. M. nitroreducens' reduces ferric iron forming ammonium (23.1 %) and nitrous oxide (N2O, 46.5 %) from nitrate. These results are supported with the upregulation of genes coding for proteins responsible for dissimilatory nitrate reduction to ammonium (nrfA), N2O formation (norV, cyt P460), and multiple multiheme c-type cytochromes for ferric iron reduction. Concomitantly, an increase in the N2O-reducing SJA-28 lineage and a decrease in the nitrite-reducing 'Candidatus Methylomirabilis oxyfera' are consistent with the changes in 'Ca. M. nitroreducens' end products. These findings demonstrate the highly flexible physiology of 'Ca. M. nitroreducens' in anaerobic ecosystems with diverse electron acceptor conditions, and further reveals its roles in linking methane oxidation to global biogeochemical cycles. 'Ca. M. nitroreducens' could significantly affect the bioavailability of nitrogen sources as well as the emission of greenhouse gas in natural ecosystems and wastewater treatment plants.
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Affiliation(s)
- Xin Tan
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China; The Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, Queensland 4072, Australia
| | - Yang Lu
- The Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, Queensland 4072, Australia
| | - Wen-Bo Nie
- Key Laboratory of the Three Gorges Region's Eco-Environment, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing 400044, China
| | - Paul Evans
- The Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, Queensland 4072, Australia.
| | - Xiao-Wei Wang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Cheng-Cheng Dang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Xuan Wang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Bing-Feng Liu
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - De-Feng Xing
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Nan-Qi Ren
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Guo-Jun Xie
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China.
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Liu L, Zheng N, Yu Y, Zheng Z, Yao H. Soil carbon and nitrogen cycles driven by iron redox: A review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 918:170660. [PMID: 38325492 DOI: 10.1016/j.scitotenv.2024.170660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Revised: 01/30/2024] [Accepted: 02/01/2024] [Indexed: 02/09/2024]
Abstract
Soil carbon and nitrogen cycles affect agricultural production, environmental quality, and global climate. Iron (Fe), regarded as the most abundant redox-active metal element in the Earth's crust, is involved in a biogeochemical cycle that includes Fe(III) reduction and Fe(II) oxidation. The redox reactions of Fe can be linked to the carbon and nitrogen cycles in soil in various ways. Investigating the transformation processes and mechanisms of soil carbon and nitrogen species driven by Fe redox can provide theoretical guidance for improving soil fertility, and addressing global environmental pollution as well as climate change. Although the widespread occurrence of these coupling processes in soils has been revealed, explorations of the effects of Fe redox on soil carbon and nitrogen cycles remain in the early stages, particularly when considering the broader context of global climate and environmental changes. The key functional microorganisms, mechanisms, and contributions of these coupling processes to soil carbon and nitrogen cycles have not been fully elucidated. Here, we present a systematic review of the research progress on soil carbon and nitrogen cycles mediated by Fe redox, including the underlying reaction processes, the key microorganisms involved, the influencing factors, and their environmental significance. Finally, some unresolved issues and future perspectives are addressed. This knowledge expands our understanding of the interconnected cycles of Fe, carbon and nitrogen in soils.
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Affiliation(s)
- Lihu Liu
- Research Center for Environmental Ecology and Engineering, Key Laboratory of Green Chemical Engineering Process of Ministry of Education, School of Environmental Ecology and Biological Engineering, Wuhan Institute of Technology, 206 Guanggu 1st Road, Wuhan 430205, PR China
| | - Ningguo Zheng
- Research Center for Environmental Ecology and Engineering, Key Laboratory of Green Chemical Engineering Process of Ministry of Education, School of Environmental Ecology and Biological Engineering, Wuhan Institute of Technology, 206 Guanggu 1st Road, Wuhan 430205, PR China
| | - Yongxiang Yu
- Research Center for Environmental Ecology and Engineering, Key Laboratory of Green Chemical Engineering Process of Ministry of Education, School of Environmental Ecology and Biological Engineering, Wuhan Institute of Technology, 206 Guanggu 1st Road, Wuhan 430205, PR China
| | - Zhaozhi Zheng
- Water Research Centre, School of Civil and Environmental Engineering, University of New South Wales, New South Wales 2052, Australia
| | - Huaiying Yao
- Research Center for Environmental Ecology and Engineering, Key Laboratory of Green Chemical Engineering Process of Ministry of Education, School of Environmental Ecology and Biological Engineering, Wuhan Institute of Technology, 206 Guanggu 1st Road, Wuhan 430205, PR China; Key Laboratory of Urban Environment and Health, Ningbo Observation and Research Station, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, PR China; Zhejiang Key Laboratory of Urban Environmental Processes and Pollution Control, CAS Haixi Industrial Technology Innovation Center in Beilun, Ningbo 315830, PR China.
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Yu L, Jia R, Liu S, Li S, Zhong S, Liu G, Zeng RJ, Rensing C, Zhou S. Ferrihydrite-mediated methanotrophic nitrogen fixation in paddy soil under hypoxia. ISME COMMUNICATIONS 2024; 4:ycae030. [PMID: 38524761 PMCID: PMC10960957 DOI: 10.1093/ismeco/ycae030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Revised: 02/21/2024] [Accepted: 02/29/2024] [Indexed: 03/26/2024]
Abstract
Biological nitrogen fixation (BNF) by methanotrophic bacteria has been shown to play an important role in maintaining fertility. However, this process is still limited to aerobic methane oxidation with sufficient oxygen. It has remained unknown whether and how methanotrophic BNF proceeds in hypoxic environments. Herein, we incubated paddy soils with a ferrihydrite-containing mineral salt medium to enrich methanotrophic bacteria in the presence of methane (20%, v/v) under oxygen constraints (0.27%, v/v). The resulting microcosms showed that ferrihydrite-dependent aerobic methane oxidation significantly contributed (81%) to total BNF, increasing the 15N fixation rate by 13-fold from 0.02 to 0.28 μmol 15N2 (g dry weight soil) -1 d-1. BNF was reduced by 97% when ferrihydrite was omitted, demonstrating the involvement of ferrihydrite in methanotrophic BNF. DNA stable-isotope probing indicated that Methylocystis, Methylophilaceae, and Methylomicrobium were the dominant methanotrophs/methylotrophs that assimilated labeled isotopes (13C or 15N) into biomass. Metagenomic binning combined with electrochemical analysis suggested that Methylocystis and Methylophilaceae had the potential to perform methane-induced BNF and likely utilized riboflavin and c-type cytochromes as electron carriers for ferrihydrite reduction. It was concluded that ferrihydrite mediated methanotrophic BNF by methanotrophs/methylotrophs solely or in conjunction with iron-reducing bacteria. Overall, this study revealed a previously overlooked yet pronounced coupling of iron-dependent aerobic methane oxidation to BNF and improves our understanding of methanotrophic BNF in hypoxic zones.
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Affiliation(s)
- Linpeng Yu
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Rong Jia
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Key Laboratory of Land Resources Evaluation and Monitoring in Southwest China, Ministry of Education, Sichuan Normal University, Chengdu, Sichuan Province 610066, China
| | - Shiqi Liu
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Shuan Li
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Sining Zhong
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Guohong Liu
- Agricultural Bio-resources Research Institute, Fujian Academy of Agricultural Sciences, Fuzhou 350003, China
| | - Raymond Jianxiong Zeng
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Christopher Rensing
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Shungui Zhou
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
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Coon GR, Duesing PD, Paul R, Baily JA, Lloyd KG. Biological methane production and accumulation under sulfate-rich conditions at Cape Lookout Bight, NC. Front Microbiol 2023; 14:1268361. [PMID: 37869653 PMCID: PMC10587565 DOI: 10.3389/fmicb.2023.1268361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 09/14/2023] [Indexed: 10/24/2023] Open
Abstract
Introduction Anaerobic oxidation of methane (AOM) is hypothesized to occur through reverse hydrogenotrophic methanogenesis in marine sediments because sulfate reducers pull hydrogen concentrations so low that reverse hydrogenotrophic methanogenesis is exergonic. If true, hydrogenotrophic methanogenesis can theoretically co-occur with sulfate reduction if the organic matter is so labile that fermenters produce more hydrogen than sulfate reducers can consume, causing hydrogen concentrations to rise. Finding accumulation of biologically-produced methane in sulfate-containing organic-rich sediments would therefore support the theory that AOM occurs through reverse hydrogenotrophic methanogenesis since it would signal the absence of net AOM in the presence of sulfate. Methods 16S rRNA gene libraries were compared to geochemistry and incubations in high depth-resolution sediment cores collected from organic-rich Cape Lookout Bight, North Carolina. Results We found that methane began to accumulate while sulfate is still abundant (6-8 mM). Methane-cycling archaea ANME-1, Methanosarciniales, and Methanomicrobiales also increased at these depths. Incubations showed that methane production in the upper 16 cm in sulfate-rich sediments was biotic since it could be inhibited by 2-bromoethanosulfonoic acid (BES). Discussion We conclude that methanogens mediate biological methane production in these organic-rich sediments at sulfate concentrations that inhibit methanogenesis in sediments with less labile organic matter, and that methane accumulation and growth of methanogens can occur under these conditions as well. Our data supports the theory that H2 concentrations, rather than the co-occurrence of sulfate and methane, control whether methanogenesis or AOM via reverse hydrogenotrophic methanogenesis occurs. We hypothesize that the high amount of labile organic matter at this site prevents AOM, allowing methane accumulation when sulfate is low but still present in mM concentrations.
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Yan Z, Du K, Yan Y, Huang R, Zhu F, Yuan X, Wang S, Ferry JG. Respiration-driven methanotrophic growth of diverse marine methanogens. Proc Natl Acad Sci U S A 2023; 120:e2303179120. [PMID: 37729205 PMCID: PMC10523532 DOI: 10.1073/pnas.2303179120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 08/04/2023] [Indexed: 09/22/2023] Open
Abstract
Anaerobic marine environments are the third largest producer of the greenhouse gas methane. The release to the atmosphere is prevented by anaerobic 'methanotrophic archaea (ANME) dependent on a symbiotic association with sulfate-reducing bacteria or direct reduction of metal oxides. Metagenomic analyses of ANME are consistent with a reverse methanogenesis pathway, although no wild-type isolates have been available for validation and biochemical investigation. Herein is reported the characterization of methanotrophic growth for the diverse marine methanogens Methanosarcina acetivorans C2A and Methanococcoides orientis sp. nov. Growth was dependent on reduction of either ferrihydrite or humic acids revealing a respiratory mode of energy conservation. Acetate and/or formate were end products. Reversal of the well-characterized methanogenic pathways is remarkably like the consensus pathways for uncultured ANME based on extensive metagenomic analyses.
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Affiliation(s)
- Zhen Yan
- Shandong Key Laboratory of Water pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao266237, China
- Suzhou Research Institute, Shandong University, Suzhou, Jiangsu215123, China
| | - Kaifeng Du
- Shandong Key Laboratory of Water pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao266237, China
| | - Yunfeng Yan
- Shandong Key Laboratory of Water pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao266237, China
| | - Rui Huang
- Shandong Key Laboratory of Water pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao266237, China
| | - Fanping Zhu
- Shandong Key Laboratory of Water pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao266237, China
| | - Xianzheng Yuan
- Shandong Key Laboratory of Water pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao266237, China
| | - Shuguang Wang
- Shandong Key Laboratory of Water pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao266237, China
| | - James G. Ferry
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA16801
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Eliani-Russak E, Tik Z, Uzi-Gavrilov S, Meijler MM, Sivan O. The reduction of environmentally abundant iron oxides by the methanogen Methanosarcina barkeri. Front Microbiol 2023; 14:1197299. [PMID: 37547683 PMCID: PMC10399698 DOI: 10.3389/fmicb.2023.1197299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 07/05/2023] [Indexed: 08/08/2023] Open
Abstract
Microbial dissimilatory iron reduction is a fundamental respiratory process that began early in evolution and is performed in diverse habitats including aquatic anoxic sediments. In many of these sediments microbial iron reduction is not only observed in its classical upper zone, but also in the methane production zone, where low-reactive iron oxide minerals are present. Previous studies in aquatic sediments have shown the potential role of the archaeal methanogen Methanosarcinales in this reduction process, and their use of methanophenazines was suggested as an advantage in reducing iron over other iron-reducing bacteria. Here we tested the capability of the methanogenic archaeon Methanosarcina barkeri to reduce three naturally abundant iron oxides in the methanogenic zone: the low-reactive iron minerals hematite and magnetite, and the high-reactive amorphous iron oxide. We also examined the potential role of their methanophenazines in promoting the reduction. Pure cultures were grown close to natural conditions existing in the methanogenic zone (under nitrogen atmosphere, N2:CO2, 80:20), in the presence of these iron oxides and different electron shuttles. Iron reduction by M. barkeri was observed in all iron oxide types within 10 days. The reduction during that time was most notable for amorphous iron, then magnetite, and finally hematite. Importantly, the reduction of iron inhibited archaeal methane production. When hematite was added inside cryogenic vials, thereby preventing direct contact with M. barkeri, no iron reduction was observed, and methanogenesis was not inhibited. This suggests a potential role of methanophenazines, which are strongly associated with the membrane, in transferring electrons from the cell to the minerals. Indeed, adding dissolved phenazines as electron shuttles to the media with iron oxides increased iron reduction and inhibited methanogenesis almost completely. When M. barkeri was incubated with hematite and the phenazines together, there was a change in the amounts (but not the type) of specific metabolites, indicating a difference in the ratio of metabolic pathways. Taken together, the results show the potential role of methanogens in reducing naturally abundant iron minerals in methanogenic sediments under natural energy and substrate limitations and shed new insights into the coupling of microbial iron reduction and the important greenhouse gas methane.
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Affiliation(s)
- Efrat Eliani-Russak
- Department of Earth and Environmental Sciences, Ben-Gurion University of the Negev, Be'er Sheva, Israel
| | - Zohar Tik
- Department of Chemistry, Ben-Gurion University of the Negev, Be'er Sheva, Israel
| | - Shaked Uzi-Gavrilov
- Department of Chemistry, Ben-Gurion University of the Negev, Be'er Sheva, Israel
| | - Michael M. Meijler
- Department of Chemistry, Ben-Gurion University of the Negev, Be'er Sheva, Israel
- The National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Be'er Sheva, Israel
| | - Orit Sivan
- Department of Earth and Environmental Sciences, Ben-Gurion University of the Negev, Be'er Sheva, Israel
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He Z, Shen J, Zhu Y, Feng J, Pan X. Enhanced anaerobic oxidation of methane with the coexistence of iron oxides and sulfate fertilizer in paddy soil. CHEMOSPHERE 2023; 329:138623. [PMID: 37030346 DOI: 10.1016/j.chemosphere.2023.138623] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Revised: 04/03/2023] [Accepted: 04/04/2023] [Indexed: 05/03/2023]
Abstract
Iron oxides and sulfate are usually abundant in paddy soil, but their role in reducing methane emissions is little known. In this work, paddy soil was anaerobically cultivated with ferrihydrite and sulfate for 380 days. An activity assay, inhibition experiment, and microbial analysis were conducted to evaluate the microbial activity, possible pathways, and community structure, respectively. The results showed that anaerobic oxidation of methane (AOM) was active in the paddy soil. The AOM activity was much higher with ferrihydrite than sulfate, and an extra 10% of AOM activity was stimulated when ferrihydrite and sulfate coexisted. The microbial community was highly similar to the duplicates but totally different with different electron acceptors. The microbial abundance and diversity decreased due to the oligotrophic condition, but mcrA-carrying archaea increased 2-3 times after 380 days. Both the microbial community and the inhibition experiment implied that there was an intersection between iron and sulfur cycles. A "cryptic sulfur cycle" might link the two cycles, in which sulfate was quickly regenerated by iron oxides, and it might contribute 33% of AOM in the tested paddy soil. Complex links between methane, iron, and sulfur geochemical cycles occur in paddy soil, which may be significant in reducing methane emissions from rice fields.
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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, China
| | - Jiaquan Shen
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou, China
| | - Yinghong Zhu
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou, China
| | - Jieni Feng
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou, China
| | - Xiangliang Pan
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou, China.
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He Z, Xu Y, Zhu Y, Feng J, Zhang D, Pan X. Long-term effects of soluble and insoluble ferric irons on anaerobic oxidation of methane in paddy soil. CHEMOSPHERE 2023; 317:137901. [PMID: 36669540 DOI: 10.1016/j.chemosphere.2023.137901] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 01/15/2023] [Accepted: 01/16/2023] [Indexed: 06/17/2023]
Abstract
Iron-dependent anaerobic oxidation of methane (Fe-AOM) is an important process to reduce methane emissions into the atmosphere. It is well known that iron bioavailability largely influences microbial iron reduction, but the long-term effects of different ferric irons on soil Fe-AOM remain unknown. In this work, paddy soil in the ferruginous zone was collected and inoculated with insoluble ferrihydrite and soluble EDTA-Fe(III) for 420 days. Stable isotope experiments, activity inhibition tests, and molecular biological techniques were performed to reveal the activity, microbial community, and possible mechanism of paddy soil Fe-AOM. The results showed that ferrihydrite was a better electron acceptor for long-term Fe-AOM cultivation. Although EDTA-Fe(III) is highly bioavailable and could stimulate Fe-AOM activity for a short time, it restricted the activity increase in the long term. The abundances of archaea, iron-reducing bacteria (IRB), and gene mcrA largely increased after cultivation, indicating the important roles of mcrA-carrying archaea and IRB. Remarkably, archaeal communities were similar, but bacteria were totally different with different ferric irons. The results of the microbial community and activity inhibition suggested that Fe-AOM was performed likely by the cooperation between archaea (Methanomassiliicoccaceae or pGrfC26) and IRB in the cultures.
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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, China
| | - Yiting Xu
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou, China
| | - Yinghong Zhu
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou, China
| | - Jieni Feng
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou, China
| | - Daoyong Zhang
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou, China
| | - Xiangliang Pan
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou, China.
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