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Wang J, Zhao Y, Zhou M, Hu J, Hu B. Aerobic and denitrifying methanotrophs: Dual wheels driving soil methane emission reduction. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 867:161437. [PMID: 36623660 DOI: 10.1016/j.scitotenv.2023.161437] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 12/16/2022] [Accepted: 01/03/2023] [Indexed: 06/17/2023]
Abstract
The greenhouse gas methane in soils has been considered to be consumed mainly by aerobic methane-oxidizing bacteria for a long time. In the last decades, the discovery of anaerobic methanotrophs greatly complemented the methane cycle, but their contribution rates and ecological significance in soils remain undescribed. In this work, the soil samples from forest, grassland and cropland in four different climatic regions were collected to investigate these conventional and novel methanotrophs. A dual-core microbial methane sink, responsible for over 80 % of soil methane emission reduction, was unveiled. The aerobic core was performed by aerobic methanotrophic bacteria in topsoil, who played important roles in stabilizing bacterial communities. The anaerobic core was denitrifying methanotrophs in anoxic soils, including denitrifying methanotrophic bacteria from NC10 phylum and denitrifying methanotrophic archaea from ANME-2d clade. They were ubiquitous in terrestrial soils and potentially led to around 50 % of the total methane removal. Human activities such as livestock farming and rice cultivation further promoted the contribution rates of these denitrifying methanotrophs. This work elucidated the emission reduction contribution of different methanotrophs in the continental setting, which would help to reduce uncertainties in the estimations of the soil methane emission.
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Affiliation(s)
- Jiaqi Wang
- Department of Environmental Engineering, Zhejiang University, Hangzhou 310058, China
| | - Yuxiang Zhao
- Department of Environmental Engineering, Zhejiang University, Hangzhou 310058, China
| | - Meng Zhou
- Department of Environmental Engineering, Zhejiang University, Hangzhou 310058, China
| | - Jiajie Hu
- Department of Environmental Engineering, Zhejiang University, Hangzhou 310058, China
| | - Baolan Hu
- Department of Environmental Engineering, Zhejiang University, Hangzhou 310058, China; Zhejiang Province Key Laboratory for Water Pollution Control and Environmental Safety, Hangzhou 310058, China.
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52
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Wang H, Jurasinski G, Täumer J, Kuß AW, Groß V, Köhn D, Günther A, Urich T. Linking Transcriptional Dynamics of Peat Microbiomes to Methane Fluxes during a Summer Drought in Two Rewetted Fens. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:5089-5101. [PMID: 36926875 DOI: 10.1021/acs.est.2c07461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Rewetted peatlands are reestablished hot spots for CH4 emissions, which are subject to increased drought events in the course of climate change. However, the dynamics of soil methane-cycling microbiomes in rewetted peatlands during summer drought are still poorly characterized. Using a quantitative metatranscriptomic approach, we investigated the changes in the transcript abundances of methanogen and methanotroph rRNA, as well as mcrA and pmoA mRNA before, during, and after the 2018 summer drought in a coastal and a percolation fen in northern Germany. Drought changed the community structure of methane-cycling microbiomes and decreased the CH4 fluxes as well as the rRNA and mRNA transcript abundances of methanogens and methanotrophs, but they showed no recovery or increase after the drought ended. The rRNA transcript abundance of methanogens was not correlated with CH4 fluxes in both fens. In the percolation fen, however, the mcrA transcript abundance showed a positive and significant correlation with CH4 fluxes. Importantly, when integrating pmoA abundance, a stronger correlation was observed between CH4 fluxes and mcrA/pmoA, suggesting that relationships between methanogens and methanotrophs are the key determinant of CH4 turnover. Our study provides a comprehensive understanding of the methane-cycling microbiome feedbacks to drought events in rewetted peatlands.
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Affiliation(s)
- Haitao Wang
- Institute of Microbiology, University of Greifswald, 17489 Greifswald, Germany
| | - Gerald Jurasinski
- Landscape Ecology, University of Rostock, 18059 Rostock, Germany
- Interdisciplinary Faculty, University of Rostock, 18059 Rostock, Germany
- Peatland Science, University of Greifswald, 17489 Greifswald, Germany
| | - Jana Täumer
- Institute of Microbiology, University of Greifswald, 17489 Greifswald, Germany
| | - Andreas W Kuß
- Human Molecular Genetics Group, Department of Functional Genomics, University Medicine Greifswald, 17489 Greifswald, Germany
| | - Verena Groß
- Institute of Microbiology, University of Greifswald, 17489 Greifswald, Germany
| | - Daniel Köhn
- Landscape Ecology, University of Rostock, 18059 Rostock, Germany
| | - Anke Günther
- Landscape Ecology, University of Rostock, 18059 Rostock, Germany
| | - Tim Urich
- Institute of Microbiology, University of Greifswald, 17489 Greifswald, Germany
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53
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Obregon Alvarez D, Fonseca de Souza L, Mendes LW, de Moraes MT, Tosi M, Venturini AM, Meyer KM, Barbosa de Camargo P, Bohannan BJM, Mazza Rodrigues JL, Dunfield KE, Tsai SM. Shifts in functional traits and interactions patterns of soil methane-cycling communities following forest-to-pasture conversion in the Amazon Basin. Mol Ecol 2023. [PMID: 36896778 DOI: 10.1111/mec.16912] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 01/24/2023] [Accepted: 02/27/2023] [Indexed: 03/11/2023]
Abstract
Deforestation threatens the integrity of the Amazon biome and the ecosystem services it provides, including greenhouse gas mitigation. Forest-to-pasture conversion has been shown to alter the flux of methane gas (CH4 ) in Amazonian soils, driving a switch from acting as a sink to a source of atmospheric CH4 . This study aimed to better understand this phenomenon by investigating soil microbial metagenomes, focusing on the taxonomic and functional structure of methane-cycling communities. Metagenomic data from forest and pasture soils were combined with measurements of in situ CH4 fluxes and soil edaphic factors and analysed using multivariate statistical approaches. We found a significantly higher abundance and diversity of methanogens in pasture soils. As inferred by co-occurrence networks, these microorganisms seem to be less interconnected within the soil microbiota in pasture soils. Metabolic traits were also different between land uses, with increased hydrogenotrophic and methylotrophic pathways of methanogenesis in pasture soils. Land-use change also induced shifts in taxonomic and functional traits of methanotrophs, with bacteria harbouring genes encoding the soluble form of methane monooxygenase enzyme (sMMO) depleted in pasture soils. Redundancy analysis and multimodel inference revealed that the shift in methane-cycling communities was associated with high pH, organic matter, soil porosity and micronutrients in pasture soils. These results comprehensively characterize the effect of forest-to-pasture conversion on the microbial communities driving the methane-cycling microorganisms in the Amazon rainforest, which will contribute to the efforts to preserve this important biome.
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Affiliation(s)
- Dasiel Obregon Alvarez
- Center for Nuclear Energy in Agriculture, University of São Paulo, Piracicaba, SP, Brazil
- School of Environmental Sciences, University of Guelph, Guelph, Ontario, Canada
| | | | - Lucas William Mendes
- Center for Nuclear Energy in Agriculture, University of São Paulo, Piracicaba, SP, Brazil
| | | | - Micaela Tosi
- School of Environmental Sciences, University of Guelph, Guelph, Ontario, Canada
| | | | - Kyle M Meyer
- Department of Integrative Biology, University of California-Berkeley, Berkeley, California, USA
- Institute of Ecology and Evolution, University of Oregon, Eugene, Oregon, USA
| | | | | | - Jorge L Mazza Rodrigues
- Department of Land, Air, and Water Resources, University of California-Davis, Davis, California, USA
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Kari E Dunfield
- School of Environmental Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Siu Mui Tsai
- Center for Nuclear Energy in Agriculture, University of São Paulo, Piracicaba, SP, Brazil
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54
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Zhu X, Deng Y, Hernández M, Fang J, Xing P, Liu Y. Distinct responses of soil methanotrophy in hummocks and hollows to simulated glacier meltwater and temperature rise in Tibetan glacier foreland. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 862:160888. [PMID: 36521618 DOI: 10.1016/j.scitotenv.2022.160888] [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: 09/08/2022] [Revised: 12/06/2022] [Accepted: 12/08/2022] [Indexed: 06/17/2023]
Abstract
Glacier foreland soils are known to be essential methane (CH4) consumers. However, global warming and increased glacier meltwater have turned some foreland meadows into swamp meadows. The potential impact of this change on the function of foreland soils in methane consumption remains unclear. Therefore, we collected Tibetan glacier foreland soils in the non-melting season from typical microtopography in swamp meadows (hummock and hollow). Three soil moisture conditions (moist, saturated, and submerged) were set by adding glacier runoff water. Soil samples were then incubated in the laboratory for two weeks at 10 °C and 20 °C. About 5 % of 13CH4/12CH4 was added to the incubation bottles, and daily methane concentrations were measured. DNA stable isotope probing (DNA-SIP) and high-throughput sequencing were combined to target the active methanotroph populations. The results showed that type Ia methanotrophs, including Crenothrix, Methylobacter, and an unclassified Methylomonadaceae cluster, actively oxidized methane at 10 °C and 20 °C. There were distinct responses of methanotrophs to soil moisture rises in hummock and hollow soils, resulting in different methane oxidation potentials. In both hummock and hollow soils, the methane oxidation potential was positively correlated with temperature. Furthermore, saturated hummock soils exhibited the highest methane oxidation potential and methanotroph populations, while submerged hollow soils had the lowest. This suggests that the in-situ hummock soils, generally saturated with water, are more essential than in-situ hollows, typically submerged in water, for alleviating the global warming potential of swamp meadows in the Tibetan glacier foreland during the growing season.
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Affiliation(s)
- Xinshu Zhu
- School of Geography, Nanjing Normal University, Nanjing 210023, China
| | - Yongcui Deng
- School of Geography, Nanjing Normal University, Nanjing 210023, China; Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing 210023, China.
| | - Marcela Hernández
- School of Biological Sciences, University of East Anglia, Norwich, Norfolk NR4 7TJ, United Kingdom
| | - Jie Fang
- School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing 210023, China
| | - Peng Xing
- Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Yongqin Liu
- Center for the Pan-third Pole Environment, Lanzhou University, Lanzhou 730000, China; State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment (TPESRE), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
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55
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Michaud AB, Massé RO, Emerson D. Microbial iron cycling is prevalent in water-logged Alaskan Arctic tundra habitats, but sensitive to disturbance. FEMS Microbiol Ecol 2023; 99:7022315. [PMID: 36725207 DOI: 10.1093/femsec/fiad013] [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: 12/06/2022] [Revised: 01/23/2023] [Accepted: 01/31/2023] [Indexed: 02/03/2023] Open
Abstract
Water logged habitats in continuous permafrost regions provide extensive oxic-anoxic interface habitats for iron cycling. The iron cycle interacts with the methane and phosphorus cycles, and is an important part of tundra biogeochemistry. Our objective was to characterize microbial communities associated with the iron cycle within natural and disturbed habitats of the Alaskan Arctic tundra. We sampled aquatic habitats within natural, undisturbed and anthropogenically disturbed areas and sequenced the 16S rRNA gene to describe the microbial communities, then supported these results with process rate and geochemical measurements. Undisturbed habitats have microbial communities that are significantly different than disturbed habitats. Microbial taxa known to participate in the iron and methane cycles are significantly associated with natural habitats, whereas they are not significantly associated with disturbed sites. Undisturbed habitats have significantly higher extractable iron and are more acidic than disturbed habitats sampled. Iron reduction is not measurable in disturbed aquatic habitats and is not stimulated by the addition of biogenic iron mats. Our study highlights the prevalence of Fe-cycling in undisturbed water-logged habitats, and demonstrates that anthropogenic disturbance of the tundra, due to legacy gravel mining, alters the microbiology of aquatic habitats and disrupts important biogeochemical cycles in the Arctic tundra.
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Affiliation(s)
- Alexander B Michaud
- Bigelow Laboratory for Ocean Sciences, East Boothbay, ME 04544, United States
| | - Rémi O Massé
- Bigelow Laboratory for Ocean Sciences, East Boothbay, ME 04544, United States
| | - David Emerson
- Bigelow Laboratory for Ocean Sciences, East Boothbay, ME 04544, United States
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56
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Wang L, Zhao M, Du X, Feng K, Gu S, Zhou Y, Yang X, Zhang Z, Wang Y, Zhang Z, Zhang Q, Xie B, Han G, Deng Y. Fungi and cercozoa regulate methane-associated prokaryotes in wetland methane emissions. Front Microbiol 2023; 13:1076610. [PMID: 36687630 PMCID: PMC9853292 DOI: 10.3389/fmicb.2022.1076610] [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: 10/21/2022] [Accepted: 12/05/2022] [Indexed: 01/09/2023] Open
Abstract
Wetlands are natural sources of methane (CH4) emissions, providing the largest contribution to the atmospheric CH4 pool. Changes in the ecohydrological environment of coastal salt marshes, especially the surface inundation level, cause instability in the CH4 emission levels of coastal ecosystems. Although soil methane-associated microorganisms play key roles in both CH4 generation and metabolism, how other microorganisms regulate methane emission and their responses to inundation has not been investigated. Here, we studied the responses of prokaryotic, fungal and cercozoan communities following 5 years of inundation treatments in a wetland experimental site, and molecular ecological networks analysis (MENs) was constructed to characterize the interdomain relationship. The result showed that the degree of inundation significantly altered the CH4 emissions, and the abundance of the pmoA gene for methanotrophs shifted more significantly than the mcrA gene for methanogens, and they both showed significant positive correlations to methane flux. Additionally, we found inundation significantly altered the diversity of the prokaryotic and fungal communities, as well as the composition of key species in interactions within prokaryotic, fungal, and cercozoan communities. Mantel tests indicated that the structure of the three communities showed significant correlations to methane emissions (p < 0.05), suggesting that all three microbial communities directly or indirectly contributed to the methane emissions of this ecosystem. Correspondingly, the interdomain networks among microbial communities revealed that methane-associated prokaryotic and cercozoan OTUs were all keystone taxa. Methane-associated OTUs were more likely to interact in pairs and correlated negatively with the fungal and cercozoan communities. In addition, the modules significantly positively correlated with methane flux were affected by environmental stress (i.e., pH) and soil nutrients (i.e., total nitrogen, total phosphorus and organic matter), suggesting that these factors tend to positively regulate methane flux by regulating microbial relationships under inundation. Our findings demonstrated that the inundation altered microbial communities in coastal wetlands, and the fungal and cercozoan communities played vital roles in regulating methane emission through microbial interactions with the methane-associated community.
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Affiliation(s)
- Linlin Wang
- Institute of Marine Science and Technology, Shandong University, Qingdao, China
| | - Mingliang Zhao
- CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, China
| | - Xiongfeng Du
- CAS Key Laboratory for Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences (CAS), Beijing, China,College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
| | - Kai Feng
- CAS Key Laboratory for Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences (CAS), Beijing, China,College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
| | - Songsong Gu
- CAS Key Laboratory for Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences (CAS), Beijing, China
| | - Yuqi Zhou
- Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, China,Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Zhejiang University, Hangzhou, China
| | - Xingsheng Yang
- CAS Key Laboratory for Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences (CAS), Beijing, China,College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
| | - Zhaojing Zhang
- Institute of Marine Science and Technology, Shandong University, Qingdao, China
| | - Yingcheng Wang
- Collage of Agriculture and Animal Husbandry, Qinghai University, Xining, China
| | - Zheng Zhang
- Institute of Marine Science and Technology, Shandong University, Qingdao, China
| | - Qi Zhang
- Institute of Marine Science and Technology, Shandong University, Qingdao, China
| | - Baohua Xie
- Yellow River Delta Field Observation and Research Station of Coastal Wetland Ecosystem, Chinese Academy of Sciences, Yantai, China,Key Laboratory of Coastal Zone Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, China
| | - Guangxuan Han
- Yellow River Delta Field Observation and Research Station of Coastal Wetland Ecosystem, Chinese Academy of Sciences, Yantai, China,Key Laboratory of Coastal Zone Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, China
| | - Ye Deng
- Institute of Marine Science and Technology, Shandong University, Qingdao, China,CAS Key Laboratory for Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences (CAS), Beijing, China,College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China,*Correspondence: Ye Deng,
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57
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Howe KL, Seitz KW, Campbell LG, Baker BJ, Thrash JC, Rabalais NN, Rogener MK, Joye SB, Mason OU. Metagenomics and metatranscriptomics reveal broadly distributed, active, novel methanotrophs in the Gulf of Mexico hypoxic zone and in the marine water column. FEMS Microbiol Ecol 2022; 99:6909064. [PMID: 36520069 PMCID: PMC9874027 DOI: 10.1093/femsec/fiac153] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 11/17/2022] [Accepted: 12/20/2022] [Indexed: 12/23/2022] Open
Abstract
The northern Gulf of Mexico (nGOM) hypoxic zone is a shallow water environment where methane, a potent greenhouse gas, fluxes from sediments to bottom water and remains trapped due to summertime stratification. When the water column is destratified, an active planktonic methanotrophic community could mitigate the efflux of methane, which accumulates to high concentrations, to the atmosphere. To investigate the possibility of such a biofilter in the nGOM hypoxic zone we performed metagenome assembly, and metagenomic and metatranscriptomic read mapping. Methane monooxygenase (pmoA) was an abundant transcript, yet few canonical methanotrophs have been reported in this environment, suggesting a role for non-canonical methanotrophs. To determine the identity of these methanotrophs, we reconstructed six novel metagenome-assembled genomes (MAGs) in the Planctomycetota, Verrucomicrobiota and one putative Latescibacterota, each with at least one pmoA gene copy. Based on ribosomal protein phylogeny, closely related microbes (mostly from Tara Oceans) and isolate genomes were selected and co-analyzed with the nGOM MAGs. Gene annotation and read mapping suggested that there is a large, diverse and unrecognized community of active aerobic methanotrophs in the nGOM hypoxic zone and in the global ocean that could mitigate methane flux to the atmosphere.
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Affiliation(s)
- Kathryn L Howe
- Department of Earth, Ocean, and Atmospheric Science, Florida State University, 32306, Tallahassee, United States
| | - Kiley W Seitz
- Department of Marine Science, Marine Science Institute, University of Texas at Austin, 78373, Port Aransas, United States
| | - Lauren G Campbell
- Department of Earth, Ocean, and Atmospheric Science, Florida State University, 32306, Tallahassee, United States
| | - Brett J Baker
- Department of Marine Science, Marine Science Institute, University of Texas at Austin, 78373, Port Aransas, United States,Department of Integrative Biology, University of Texas at Austin, 78712, Austin, United States
| | - J Cameron Thrash
- Department of Biological Sciences, University of Southern California, 90089, Los Angeles, United States
| | - Nancy N Rabalais
- Department of Oceanography and Coastal Sciences, Louisiana State University, 70803, Baton Rouge, United States,Louisiana Universities Marine Consortium, 70344, Chauvin, United States
| | - Mary-Kate Rogener
- Department of Marine Sciences, University of Georgia, 30602, Athens, United States
| | - Samantha B Joye
- Department of Marine Sciences, University of Georgia, 30602, Athens, United States
| | - Olivia U Mason
- Corresponding author: Department of Earth, Ocean and Atmospheric Science, Florida State University, Tallahassee, FL 32306, United States. E-mail:
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58
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Khmelenina VN, But SY, Rozova ON, Oshkin IY, Pimenov NV, Dedysh SN. Genome Editing in Methanotrophic Bacteria: Potential Targets and Available Tools. Microbiology (Reading) 2022. [DOI: 10.1134/s0026261722602196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
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59
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Cheng X, Wang H, Zeng Z, Li L, Zhao R, Bodelier PLE, Wang Y, Liu X, Su C, Liu S. Niche differentiation of atmospheric methane-oxidizing bacteria and their community assembly in subsurface karst caves. ENVIRONMENTAL MICROBIOLOGY REPORTS 2022; 14:886-896. [PMID: 35925016 DOI: 10.1111/1758-2229.13112] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 07/05/2022] [Accepted: 07/17/2022] [Indexed: 06/17/2023]
Abstract
Karst caves are recently proposed as atmospheric methane sinks in terrestrial ecosystems. Despite of the detection of atmospheric methane-oxidizing bacteria (atmMOB) in caves, we still know little about their ecology and potential ability of methane oxidation in this ecosystem. To understand atmMOB ecology and their potential in methane consumption, we collected weathered rocks and sediments from three different caves in southwestern China. We determined the potential methane oxidization rates in the range of 1.25 ± 0.08 to 1.87 ± 0.41 ng CH4 g-1 DW h-1 , which are comparable to those reported in forest and grassland soils. Results showed that alkaline oligotrophic caves harbour high numbers of atmMOB, particularly upland soil cluster (USC), which significantly correlated with temperature, CH4 and CO2 concentrations. The absolute abundance of USCγ was higher than that of USCα. USCγ-OPS (open patch soil) and USCγ-SS (subsurface soil) dominated in most samples, whereas USCα-BFS (boreal forest soil) only predominated in the sediments near cave entrances, indicating niche differentiation of atmMOB in caves. Overwhelming dominance of homogenous selection in community assembly resulted in convergence of atmMOB communities. Collectively, our results demonstrated the niche differentiation of USC in subsurface alkaline caves and their non-negligible methane-oxidizing potential, providing brand-new knowledge about atmMOB ecology in subsurface biosphere.
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Affiliation(s)
- Xiaoyu Cheng
- State Key Laboratory of Geobiology and Environmental Geology, China University of Geosciences, Wuhan, P. R. China
- School of Environmental Studies, China University of Geosciences, Wuhan, P. R. China
| | - Hongmei Wang
- State Key Laboratory of Geobiology and Environmental Geology, China University of Geosciences, Wuhan, P. R. China
- School of Environmental Studies, China University of Geosciences, Wuhan, P. R. China
| | - Zhilin Zeng
- State Key Laboratory of Geobiology and Environmental Geology, China University of Geosciences, Wuhan, P. R. China
- School of Environmental Studies, China University of Geosciences, Wuhan, P. R. China
| | - Lu Li
- State Key Laboratory of Geobiology and Environmental Geology, China University of Geosciences, Wuhan, P. R. China
- School of Environmental Studies, China University of Geosciences, Wuhan, P. R. China
| | - Rui Zhao
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Paul L E Bodelier
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
| | - Yiheng Wang
- State Key Laboratory of Geobiology and Environmental Geology, China University of Geosciences, Wuhan, P. R. China
- School of Environmental Studies, China University of Geosciences, Wuhan, P. R. China
| | - Xiaoyan Liu
- State Key Laboratory of Geobiology and Environmental Geology, China University of Geosciences, Wuhan, P. R. China
- School of Environmental Studies, China University of Geosciences, Wuhan, P. R. China
| | - Chuntian Su
- CAGS/Key Laboratory of Karst Dynamics, Institute of Karst Geology, Chinese Academy of Geological Sciences, Guilin, P. R. China
| | - Shuangjiang Liu
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, P. R. China
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60
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Barret M, Gandois L, Thalasso F, Martinez Cruz K, Sepulveda Jauregui A, Lavergne C, Teisserenc R, Aguilar P, Gerardo Nieto O, Etchebehere C, Martins Dellagnezze B, Bovio Winkler P, Fochesatto GJ, Tananaev N, Svenning MM, Seppey C, Tveit A, Chamy R, Astorga España MS, Mansilla A, Van de Putte A, Sweetlove M, Murray AE, Cabrol L. A combined microbial and biogeochemical dataset from high-latitude ecosystems with respect to methane cycle. Sci Data 2022; 9:674. [PMID: 36333353 PMCID: PMC9636175 DOI: 10.1038/s41597-022-01759-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 10/04/2022] [Indexed: 11/06/2022] Open
Abstract
High latitudes are experiencing intense ecosystem changes with climate warming. The underlying methane (CH4) cycling dynamics remain unresolved, despite its crucial climatic feedback. Atmospheric CH4 emissions are heterogeneous, resulting from local geochemical drivers, global climatic factors, and microbial production/consumption balance. Holistic studies are mandatory to capture CH4 cycling complexity. Here, we report a large set of integrated microbial and biogeochemical data from 387 samples, using a concerted sampling strategy and experimental protocols. The study followed international standards to ensure inter-comparisons of data amongst three high-latitude regions: Alaska, Siberia, and Patagonia. The dataset encompasses different representative environmental features (e.g. lake, wetland, tundra, forest soil) of these high-latitude sites and their respective heterogeneity (e.g. characteristic microtopographic patterns). The data included physicochemical parameters, greenhouse gas concentrations and emissions, organic matter characterization, trace elements and nutrients, isotopes, microbial quantification and composition. This dataset addresses the need for a robust physicochemical framework to conduct and contextualize future research on the interactions between climate change, biogeochemical cycles and microbial communities at high-latitudes. Measurement(s) | microbial diversity • microbial abundances • cations and anions • trace elements | Technology Type(s) | MiSeq sequencing 16S rRNA gene • Real Time PCR • HPLC • ICP-MS | Sample Characteristic - Organism | bacteria • archaea | Sample Characteristic - Environment | lake water • lake sediment • wetland • peatland • soil • pond | Sample Characteristic - Location | Western Siberia • Alaska • Patagonia • Cape Horn province • Magellanic subantarctic ecoregion |
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61
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Kang H, Lee J, Zhou X, Kim J, Yang Y. The Effects of N Enrichment on Microbial Cycling of Non-CO 2 Greenhouse Gases in Soils-a Review and a Meta-analysis. MICROBIAL ECOLOGY 2022; 84:945-957. [PMID: 34725713 DOI: 10.1007/s00248-021-01911-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 10/25/2021] [Indexed: 06/13/2023]
Abstract
Terrestrial ecosystems are typically nitrogen (N) limited, but recent years have witnessed N enrichment in various soil ecosystems caused by human activities such as fossil fuel combustion and fertilizer application. This enrichment may alter microbial processes in soils in a way that would increase the emissions of methane (CH4) and nitrous oxide (N2O), thereby aggravating global climate change. This review focuses on the effects of N enrichment on methanogens and methanotrophs, which play a central role in the dynamics of CH4 at the global scale. We also address the effects of N enrichment on N2O, which is produced in soils mainly by nitrification and denitrification. Overall, N enrichment inhibits methanogenesis in pure culture experiments, while its effects on CH4 oxidation are more complicated. The majority of previous studies reported that N enrichment, especially NH4+ enrichment, inhibits CH4 oxidation, resulting in higher CH4 emissions from soils. However, both activation and neutral responses have also been reported, particularly in rice paddies and landfill sites, which is well reflected in our meta-analysis. In contrast, N enrichment substantially increases N2O emission by both nitrification and denitrification, which increases proportionally to the amount of N amended. Future studies should address the effects of N enrichment on the active microbes of those functional groups at multiple scales along with parameterization of microbial communities for the application to climate models at the global scale.
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Affiliation(s)
- Hojeong Kang
- School of Civil and Environmental Engineering, Yonsei University, Seoul, Korea.
| | - Jaehyun Lee
- School of Civil and Environmental Engineering, Yonsei University, Seoul, Korea
| | - Xue Zhou
- School of Civil and Environmental Engineering, Yonsei University, Seoul, Korea
- College of Agricultural Science and Engineering, Hohai University, Nanjing, China
| | - Jinhyun Kim
- School of Civil and Environmental Engineering, Yonsei University, Seoul, Korea
| | - Yerang Yang
- School of Civil and Environmental Engineering, Yonsei University, Seoul, Korea
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Ho A, Zuan ATK, Mendes LW, Lee HJ, Zulkeflee Z, van Dijk H, Kim PJ, Horn MA. Aerobic Methanotrophy and Co-occurrence Networks of a Tropical Rainforest and Oil Palm Plantations in Malaysia. MICROBIAL ECOLOGY 2022; 84:1154-1165. [PMID: 34716776 PMCID: PMC9747831 DOI: 10.1007/s00248-021-01908-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Accepted: 10/21/2021] [Indexed: 05/11/2023]
Abstract
Oil palm (OP) plantations are gradually replacing tropical rainforest in Malaysia, one of the largest palm oil producers globally. Conversion of lands to OP plantations has been associated with compositional shifts of the microbial community, with consequences on the greenhouse gas (GHG) emissions. While the impact of the change in land use has recently been investigated for microorganisms involved in N2O emission, the response of the aerobic methanotrophs to OP agriculture remains to be determined. Here, we monitored the bacterial community composition, focusing on the aerobic methanotrophs, in OP agricultural soils since 2012, 2006, and 1993, as well as in a tropical rainforest, in 2019 and 2020. High-affinity methane uptake was confirmed, showing significantly lower rates in the OP plantations than in the tropical rainforest, but values increased with continuous OP agriculture. The bacterial, including the methanotrophic community composition, was modified with ongoing OP agriculture. The methanotrophic community composition was predominantly composed of unclassified methanotrophs, with the canonical (Methylocystis) and putative methanotrophs thought to catalyze high-affinity methane oxidation present at higher relative abundance in the oldest OP plantation. Results suggest that the methanotrophic community was relatively more stable within each site, exhibiting less temporal variations than the total bacterial community. Uncharacteristically, a 16S rRNA gene-based co-occurrence network analysis revealed a more complex and connected community in the OP agricultural soil, which may influence the resilience of the bacterial community to disturbances. Overall, we provide a first insight into the ecology and role of the aerobic methanotrophs as a methane sink in OP agricultural soils.
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Affiliation(s)
- Adrian Ho
- Institute for Microbiology, Leibniz Universität Hannover, Hannover, Germany.
| | - Ali Tan Kee Zuan
- Department of Land Management, Faculty of Agriculture, Universiti Putra Malaysia, Seri Kembangan, Selangor, Malaysia
| | - Lucas W Mendes
- Center for Nuclear Energy in Agriculture, University of São Paulo (CENA-USP), Sao Paulo, Brazil
| | - Hyo Jung Lee
- Department of Biology, Kunsan National University, Gunsan, South Korea
| | - Zufarzaana Zulkeflee
- Department of Environment, Faculty of Forestry and Environment, Universiti Putra Malaysia, Seri Kembangan, Selangor, Malaysia
| | - Hester van Dijk
- Institute for Microbiology, Leibniz Universität Hannover, Hannover, Germany
| | - Pil Joo Kim
- Division of Applied Life Science, Gyeongsang National University, Jinju, South Korea
| | - Marcus A Horn
- Institute for Microbiology, Leibniz Universität Hannover, Hannover, Germany
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63
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Cupples AM, Li Z, Wilson FP, Ramalingam V, Kelly A. In silico analysis of soil, sediment and groundwater microbial communities to predict biodegradation potential. J Microbiol Methods 2022; 202:106595. [DOI: 10.1016/j.mimet.2022.106595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 09/30/2022] [Accepted: 09/30/2022] [Indexed: 12/27/2022]
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Methylocystis sp. Strain SC2 Acclimatizes to Increasing NH 4+ Levels by a Precise Rebalancing of Enzymes and Osmolyte Composition. mSystems 2022; 7:e0040322. [PMID: 36154142 PMCID: PMC9600857 DOI: 10.1128/msystems.00403-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
A high NH4+ load is known to inhibit bacterial methane oxidation. This is due to a competition between CH4 and NH3 for the active site of particulate methane monooxygenase (pMMO), which converts CH4 to CH3OH. Here, we combined global proteomics with amino acid profiling and nitrogen oxides measurements to elucidate the cellular acclimatization response of Methylocystis sp. strain SC2 to high NH4+ levels. Relative to 1 mM NH4+, a high (50 mM and 75 mM) NH4+ load under CH4-replete conditions significantly increased the lag phase duration required for proteome adjustment. The number of differentially regulated proteins was highly significantly correlated with an increasing NH4+ load. The cellular responses to increasing ionic and osmotic stress involved a significant upregulation of stress-responsive proteins, the K+ "salt-in" strategy, the synthesis of compatible solutes (glutamate and proline), and the induction of the glutathione metabolism pathway. A significant increase in the apparent Km value for CH4 oxidation during the growth phase was indicative of increased pMMO-based oxidation of NH3 to toxic hydroxylamine. The detoxifying activity of hydroxlyamine oxidoreductase (HAO) led to a significant accumulation of NO2- and, upon decreasing O2 tension, N2O. Nitric oxide reductase and hybrid cluster proteins (Hcps) were the candidate enzymes for the production of N2O. In summary, strain SC2 has the capacity to precisely rebalance enzymes and osmolyte composition in response to increasing NH4+ exposure, but the need to simultaneously combat both ionic-osmotic stress and the toxic effects of hydroxylamine may be the reason why its acclimatization capacity is limited to 75 mM NH4+. IMPORTANCE In addition to reducing CH4 emissions from wetlands and landfills, the activity of alphaproteobacterial methane oxidizers of the genus Methylocystis contributes to the sink capacity of forest and grassland soils for atmospheric methane. The methane-oxidizing activity of Methylocystis spp. is, however, sensitive to high NH4+ concentrations. This is due to the competition of CH4 and NH3 for the active site of particulate methane monooxygenase, thereby resulting in the production of toxic hydroxylamine with an increasing NH4+ load. An understanding of the physiological and molecular response mechanisms of Methylocystis spp. is therefore of great importance. Here, we combined global proteomics with amino acid profiling and NOx measurements to disentangle the cellular mechanisms underlying the acclimatization of Methylocystis sp. strain SC2 to an increasing NH4+ load.
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Venturini AM, Dias NMS, Gontijo JB, Yoshiura CA, Paula FS, Meyer KM, Nakamura FM, da França AG, Borges CD, Barlow J, Berenguer E, Nüsslein K, Rodrigues JLM, Bohannan BJM, Tsai SM. Increased soil moisture intensifies the impacts of forest-to-pasture conversion on methane emissions and methane-cycling communities in the Eastern Amazon. ENVIRONMENTAL RESEARCH 2022; 212:113139. [PMID: 35337832 DOI: 10.1016/j.envres.2022.113139] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2021] [Revised: 02/24/2022] [Accepted: 03/15/2022] [Indexed: 06/14/2023]
Abstract
Climatic changes are altering precipitation patterns in the Amazon and may influence soil methane (CH4) fluxes due to the differential responses of methanogenic and methanotrophic microorganisms. However, it remains unclear if these climate feedbacks can amplify land-use-related impacts on the CH4 cycle. To better predict the responses of soil CH4-cycling microorganisms and emissions under altered moisture levels in the Eastern Brazilian Amazon, we performed a 30-day microcosm experiment manipulating the moisture content (original moisture; 60%, 80%, and 100% of field capacity - FC) of forest and pasture soils. Gas samples were collected periodically for gas chromatography analysis, and methanogenic archaeal and methanotrophic bacterial communities were assessed using quantitative PCR and metagenomics. Positive and negative daily CH4 fluxes were observed for forest and pasture, indicating that these soils can act as both CH4 sources and sinks. Cumulative emissions and the abundance of methanogenesis-related genes and taxonomic groups were affected by land use, moisture, and their interaction. Pasture soils at 100% FC had the highest abundance of methanogens and CH4 emissions, 22 times higher than forest soils under the same treatment. Higher ratios of methanogens to methanotrophs were found in pasture than in forest soils, even at field capacity conditions. Land use and moisture were significant factors influencing the composition of methanogenic and methanotrophic communities. The diversity and evenness of methanogens did not change throughout the experiment. In contrast, methanotrophs exhibited the highest diversity and evenness in pasture soils at 100% FC. Taken together, our results suggest that increased moisture exacerbates soil CH4 emissions and microbial responses driven by land-use change in the Amazon. This is the first report on the microbial CH4 cycle in Amazonian upland soils that combined one-month gas measurements with advanced molecular methods.
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Affiliation(s)
- Andressa M Venturini
- Cell and Molecular Biology Laboratory, Center for Nuclear Energy in Agriculture, University of São Paulo, Piracicaba, SP, 13416-000, Brazil; Princeton Institute for International and Regional Studies, Princeton University, Princeton, NJ, 08544, USA.
| | - Naissa M S Dias
- Environmental Biogeochemistry Laboratory, Center for Nuclear Energy in Agriculture, University of São Paulo, Piracicaba, SP, 13416-000, Brazil
| | - Júlia B Gontijo
- Cell and Molecular Biology Laboratory, Center for Nuclear Energy in Agriculture, University of São Paulo, Piracicaba, SP, 13416-000, Brazil
| | - Caio A Yoshiura
- Cell and Molecular Biology Laboratory, Center for Nuclear Energy in Agriculture, University of São Paulo, Piracicaba, SP, 13416-000, Brazil
| | - Fabiana S Paula
- Cell and Molecular Biology Laboratory, Center for Nuclear Energy in Agriculture, University of São Paulo, Piracicaba, SP, 13416-000, Brazil; Department of Biological Oceanography, Oceanographic Institute, University of São Paulo, São Paulo, SP, 05508-120, Brazil
| | - Kyle M Meyer
- Institute of Ecology and Evolution, University of Oregon, Eugene, OR, 97403, USA; Department of Integrative Biology, University of California - Berkeley, Berkeley, CA, 94720, USA
| | - Fernanda M Nakamura
- Cell and Molecular Biology Laboratory, Center for Nuclear Energy in Agriculture, University of São Paulo, Piracicaba, SP, 13416-000, Brazil
| | - Aline G da França
- Cell and Molecular Biology Laboratory, Center for Nuclear Energy in Agriculture, University of São Paulo, Piracicaba, SP, 13416-000, Brazil
| | - Clovis D Borges
- Cell and Molecular Biology Laboratory, Center for Nuclear Energy in Agriculture, University of São Paulo, Piracicaba, SP, 13416-000, Brazil
| | - Jos Barlow
- Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ, UK
| | - Erika Berenguer
- Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ, UK; Environmental Change Institute, University of Oxford, Oxford, OX1 3QY, UK
| | - Klaus Nüsslein
- Department of Microbiology, University of Massachusetts, Amherst, MA, 01003, USA
| | - Jorge L M Rodrigues
- Department of Land, Air, and Water Resources, University of California - Davis, Davis, CA, 95616, USA
| | - Brendan J M Bohannan
- Institute of Ecology and Evolution, University of Oregon, Eugene, OR, 97403, USA
| | - Siu M Tsai
- Cell and Molecular Biology Laboratory, Center for Nuclear Energy in Agriculture, University of São Paulo, Piracicaba, SP, 13416-000, Brazil
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Insights into the Genomic Potential of a Methylocystis sp. from Amazonian Floodplain Sediments. Microorganisms 2022; 10:microorganisms10091747. [PMID: 36144349 PMCID: PMC9506196 DOI: 10.3390/microorganisms10091747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 07/23/2022] [Accepted: 08/02/2022] [Indexed: 11/26/2022] Open
Abstract
Although floodplains are recognized as important sources of methane (CH4) in the Amazon basin, little is known about the role of methanotrophs in mitigating CH4 emissions in these ecosystems. Our previous data reported the genus Methylocystis as one of the most abundant methanotrophs in these floodplain sediments. However, information on the functional potential and life strategies of these organisms living under seasonal flooding is still missing. Here, we described the first metagenome-assembled genome (MAG) of a Methylocystis sp. recovered from Amazonian floodplains sediments, and we explored its functional potential and ecological traits through phylogenomic, functional annotation, and pan-genomic approaches. Both phylogenomics and pan-genomics identified the closest placement of the bin.170_fp as Methylocystis parvus. As expected for Type II methanotrophs, the Core cluster from the pan-genome comprised genes for CH4 oxidation and formaldehyde assimilation through the serine pathway. Furthermore, the complete set of genes related to nitrogen fixation is also present in the Core. Interestingly, the MAG singleton cluster revealed the presence of unique genes related to nitrogen metabolism and cell motility. The study sheds light on the genomic characteristics of a dominant, but as yet unexplored methanotroph from the Amazonian floodplains. By exploring the genomic potential related to resource utilization and motility capability, we expanded our knowledge on the niche breadth of these dominant methanotrophs in the Amazonian floodplains.
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Allenby A, Cunningham MR, Hillebrand-Voiculescu A, Comte JC, Doherty R, Kumaresan D. Occurrence of methane-oxidizing bacteria and methanogenic archaea in earth’s cave systems—A metagenomic analysis. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.909865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Karst ecosystems represent up to 25% of the land surface and recent studies highlight their potential role as a sink for atmospheric methane. Despite this, there is limited knowledge of the diversity and distribution of methane-oxidizing bacteria (MOB) or methanogens in karst caves and the sub-surface environment in general. Here, we performed a survey of 14 shotgun metagenomes from cave ecosystems covering a broad set of environmental conditions, to compare the relative abundance and phylogenetic diversity of MOB and methanogens, targeting biomarker genes for methane monooxygenase (pmoA and mmoX) and methyl-coenzyme M reductase (mcrA). Taxonomic analysis of metagenomes showed 0.02–1.28% of classified reads were related to known MOB, of which Gammaproteobacterial MOB were the most abundant making up on average 70% of the surveyed caves’ MOB community. Potential for biogenic methane production in caves was also observed, with 0.008–0.39% of reads classified to methanogens and was dominated by sequences related to Methanosarcina. We have also generated a cave ecosystems protein database (CEPD) based on protein level assembly of cave metagenomes that can be used to profile genes of interest.
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Diversity and Composition of Methanotroph Communities in Caves. Microbiol Spectr 2022; 10:e0156621. [PMID: 35943259 PMCID: PMC9430973 DOI: 10.1128/spectrum.01566-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Methane oxidizing microorganisms (methanotrophs) are ubiquitous in the environment and represent a major sink for the greenhouse gas methane (CH4). Recent studies have demonstrated methanotrophs are abundant and contribute to CH4 dynamics in caves. However, very little is known about what controls the distribution and abundance of methanotrophs in subterranean ecosystems. Here, we report a survey of soils collected from > 20 caves in North America to elucidate the factors shaping cave methanotroph communities. Using 16S rRNA sequencing, we recovered methanotrophs from nearly all (98%) of the samples, including cave sites where CH4 concentrations were at or below detection limits (≤0.3 ppmv). We identified a core methanotroph community among caves comprised of high-affinity methanotrophs. Although associated with local-scale mineralogy, methanotroph composition did not systematically vary between the entrances and interior of caves, where CH4 concentrations varied. We also observed methanotrophs are able to disperse readily between cave systems showing these organisms have low barriers to dispersal. Lastly, the relative abundance of methanotrophs was positively correlated with cave-air CH4 concentrations, suggesting these microorganisms contribute to CH4 flux in subterranean ecosystems. IMPORTANCE Recent observations have shown the atmospheric greenhouse gas methane (CH4) is consumed by microorganisms (methanotrophs) in caves at rates comparable to CH4 oxidation in surface soils. Caves are abundant in karst landscapes that comprise 14% of Earth’s land surface area, and therefore may represent a potentially important, but overlooked, CH4 sink. We sampled cave soils to gain a better understand the community composition and structure of cave methanotrophs. Our results show the members of the USC-γ clade are dominant in cave communities and can easily disperse through the environment, methanotroph relative abundance was correlated with local scale mineralogy of soils, and the relative abundance of methanotrophs was positively correlated with CH4 concentrations in cave air.
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Täumer J, Marhan S, Groß V, Jensen C, Kuss AW, Kolb S, Urich T. Linking transcriptional dynamics of CH 4-cycling grassland soil microbiomes to seasonal gas fluxes. THE ISME JOURNAL 2022; 16:1788-1797. [PMID: 35388141 PMCID: PMC9213473 DOI: 10.1038/s41396-022-01229-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 03/07/2022] [Accepted: 03/21/2022] [Indexed: 11/09/2022]
Abstract
Soil CH4 fluxes are driven by CH4-producing and -consuming microorganisms that determine whether soils are sources or sinks of this potent greenhouse gas. To date, a comprehensive understanding of underlying microbiome dynamics has rarely been obtained in situ. Using quantitative metatranscriptomics, we aimed to link CH4-cycling microbiomes to net surface CH4 fluxes throughout a year in two grassland soils. CH4 fluxes were highly dynamic: both soils were net CH4 sources in autumn and winter and sinks in spring and summer, respectively. Correspondingly, methanogen mRNA abundances per gram soil correlated well with CH4 fluxes. Methanotroph to methanogen mRNA ratios were higher in spring and summer, when the soils acted as net CH4 sinks. CH4 uptake was associated with an increased proportion of USCα and γ pmoA and pmoA2 transcripts. We assume that methanogen transcript abundance may be useful to approximate changes in net surface CH4 emissions from grassland soils. High methanotroph to methanogen ratios would indicate CH4 sink properties. Our study links for the first time the seasonal transcriptional dynamics of CH4-cycling soil microbiomes to gas fluxes in situ. It suggests mRNA transcript abundances as promising indicators of dynamic ecosystem-level processes.
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Affiliation(s)
- Jana Täumer
- Institute of Microbiology, Center for Functional Genomics of Microbes, University of Greifswald, Greifswald, Germany
| | - Sven Marhan
- Institute of Soil Science and Land Evaluation, Soil Biology Department, University of Hohenheim, Stuttgart, Germany
| | - Verena Groß
- Institute of Microbiology, Center for Functional Genomics of Microbes, University of Greifswald, Greifswald, Germany
| | - Corinna Jensen
- Human Molecular Genetics Group, Department of Functional Genomics, University Medicine Greifswald, Greifswald, Germany
| | - Andreas W Kuss
- Human Molecular Genetics Group, Department of Functional Genomics, University Medicine Greifswald, Greifswald, Germany
| | - Steffen Kolb
- RA Landscape Functioning, Leibniz Centre for Agricultural Landscape Research (ZALF), Müncheberg, Germany.,Thaer Institute, Faculty of Life Sciences, Humboldt University of Berlin, Berlin, Germany
| | - Tim Urich
- Institute of Microbiology, Center for Functional Genomics of Microbes, University of Greifswald, Greifswald, Germany.
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Tentori EF, Fang S, Richardson RE. RNA Biomarker Trends across Type I and Type II Aerobic Methanotrophs in Response to Methane Oxidation Rates and Transcriptome Response to Short-Term Methane and Oxygen Limitation in Methylomicrobium album BG8. Microbiol Spectr 2022; 10:e0000322. [PMID: 35678574 PMCID: PMC9241951 DOI: 10.1128/spectrum.00003-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 05/21/2022] [Indexed: 11/26/2022] Open
Abstract
Methanotrophs, which help regulate atmospheric levels of methane, are active in diverse natural and man-made environments. This range of habitats and the feast-famine cycles seen by many environmental methanotrophs suggest that methanotrophs dynamically mediate rates of methane oxidation. Global methane budgets require ways to account for this variability in time and space. Functional gene biomarker transcripts are increasingly studied to inform the dynamics of diverse biogeochemical cycles. Previously, per-cell transcript levels of the methane oxidation biomarker pmoA were found to vary quantitatively with respect to methane oxidation rates in the model aerobic methanotroph Methylosinus trichosporium OB3b. In the present study, these trends were explored for two additional aerobic methanotroph pure cultures grown in membrane bioreactors, Methylocystis parvus OBBP and Methylomicrobium album BG8. At steady-state conditions, per-cell pmoA mRNA transcript levels strongly correlated with per-cell methane oxidation across the three methanotrophs across many orders of magnitude of activity (R2 = 0.91). The inclusion of both type I and type II aerobic methanotrophs suggests a universal trend between in situ activity level and pmoA RNA biomarker levels which can aid in improving estimates of both subsurface and atmospheric methane. Additionally, genome-wide expression data (obtained by transcriptome sequencing [RNA-seq]) were used to explore transcriptomic responses of steady-state M. album BG8 cultures to short-term CH4 and O2 limitation. These limitations induced regulation of genes involved in central carbon metabolism (including carbon storage), cell motility, and stress response. IMPORTANCE Methanotrophs are naturally occurring microorganisms capable of oxidizing methane, having an impact on global net methane emissions. Additionally, they have also gained interest for their biotechnological applications in single-cell protein production, biofuels, and bioplastics. Having better ways of measuring methanotroph activity and understanding how methanotrophs respond to changing conditions is imperative for both optimization in controlled-growth applications and understanding in situ methane oxidation rates. In this study, we explored the applicability of methane oxidation biomarkers as a universal indicator of methanotrophic activity and explored methanotroph transcriptomic response to short-term changes in substrate availability. Our results contribute to better understanding the activity of aerobic methanotrophs, their core metabolic pathways, and their stress responses.
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Affiliation(s)
- Egidio F. Tentori
- School of Civil and Environmental Engineering, Cornell University, Ithaca, New York, USA
| | - Shania Fang
- School of Civil and Environmental Engineering, Cornell University, Ithaca, New York, USA
| | - Ruth E. Richardson
- School of Civil and Environmental Engineering, Cornell University, Ithaca, New York, USA
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71
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Steinsdóttir HGR, Schauberger C, Mhatre S, Thamdrup B, Bristow LA. Aerobic and anaerobic methane oxidation in a seasonally anoxic basin. LIMNOLOGY AND OCEANOGRAPHY 2022; 67:1257-1273. [PMID: 36248250 PMCID: PMC9540798 DOI: 10.1002/lno.12074] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 02/14/2022] [Accepted: 03/14/2022] [Indexed: 06/16/2023]
Abstract
Shallow coastal waters are dynamic environments that dominate global marine methane emissions. Particularly high methane concentrations are found in seasonally anoxic waters, which are spreading in eutrophic coastal systems, potentially leading to increased methane emissions to the atmosphere. Here we explore how the seasonal development of anoxia influenced methane concentrations, rates of methane oxidation, and the community composition of methanotrophs in the shallow eutrophic water column of Mariager Fjord, Denmark. Our results show the development of steep concentration gradients toward the oxic-anoxic interface as methane accumulated to 1.4 μM in anoxic bottom waters. Yet, the fjord possessed an efficient microbial methane filter near the oxic-anoxic interface that responded to the increasing methane flux. In experimental incubations, methane oxidation near the oxic-anoxic interface proceeded both aerobically and anaerobically with nearly equal efficiency reaching turnover rates as high as 0.6 and 0.8 d-1, respectively, and was seemingly mediated by members of the Methylococcales belonging to the Deep Sea-1 clade. Throughout the period, both aerobic and anaerobic methane oxidation rates were high enough to consume the estimated methane flux. Thus, our results indicate that seasonal anoxia did not increase methane emissions.
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Affiliation(s)
| | | | - Snehit Mhatre
- Department of BiologyUniversity of Southern DenmarkOdenseDenmark
| | - Bo Thamdrup
- Department of BiologyUniversity of Southern DenmarkOdenseDenmark
| | - Laura A. Bristow
- Department of BiologyUniversity of Southern DenmarkOdenseDenmark
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72
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Costa OYA, de Hollander M, Kuramae EE, Bodelier PLE. PhyloFunDB: A Pipeline to Create and Update Functional Gene Taxonomic Databases. Microorganisms 2022; 10:microorganisms10061093. [PMID: 35744611 PMCID: PMC9229802 DOI: 10.3390/microorganisms10061093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 05/17/2022] [Accepted: 05/23/2022] [Indexed: 12/04/2022] Open
Abstract
The increase in sequencing capacity has amplified the number of taxonomically unclassified sequences in most databases. The classification of such sequences demands phylogenetic tree construction and comparison to currently classified sequences, a process that demands the processing of large amounts of data and use of several different software. Here, we present PhyloFunDB, a pipeline for extracting, processing, and inferring phylogenetic trees from specific functional genes. The goal of our work is to decrease processing time and facilitate the grouping of sequences that can be used for improved taxonomic classification of functional gene datasets.
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Affiliation(s)
- Ohana Y. A. Costa
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), 6708 PB Wageningen, The Netherlands; (O.Y.A.C.); (M.d.H.); (E.E.K.)
| | - Mattias de Hollander
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), 6708 PB Wageningen, The Netherlands; (O.Y.A.C.); (M.d.H.); (E.E.K.)
- Department of Terrestrial Ecology Bioinformatics Unit, Netherlands Institute of Ecology (NIOO-KNAW), 6708 PB Wageningen, The Netherlands
| | - Eiko E. Kuramae
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), 6708 PB Wageningen, The Netherlands; (O.Y.A.C.); (M.d.H.); (E.E.K.)
- Ecology and Biodiversity Group, Department of Biology, Institute of Environmental Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Paul L. E. Bodelier
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), 6708 PB Wageningen, The Netherlands; (O.Y.A.C.); (M.d.H.); (E.E.K.)
- Correspondence:
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The Proteobacterial Methanotroph Methylosinus trichosporium OB3b Remodels Membrane Lipids in Response to Phosphate Limitation. mBio 2022; 13:e0024722. [PMID: 35575546 PMCID: PMC9239053 DOI: 10.1128/mbio.00247-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
Methane is a potent greenhouse gas in the atmosphere, and its concentration has continued to increase in recent decades. Aerobic methanotrophs, bacteria that use methane as the sole carbon source, are an important biological sink for methane, and they are widely distributed in the natural environment. However, relatively little is known on how methanotroph activity is regulated by nutrients, particularly phosphorus (P). P is the principal nutrient constraining plant and microbial productivity in many ecosystems, ranging from agricultural land to the open ocean. Using a model methanotrophic bacterium, Methylosinus trichosporium OB3b, we demonstrate here that this bacterium can produce P-free glycolipids to replace membrane phospholipids in response to P limitation. The formation of the glycolipid monoglucuronic acid diacylglycerol requires plcP-agt genes since the plcP-agt mutant is unable to produce this glycolipid. This plcP-agt-mediated lipid remodeling pathway appears to be important for M. trichosporium OB3b to cope with P stress, and the mutant grew significantly slower under P limitation. Interestingly, comparative genomics analysis shows that the ability to perform lipid remodeling appears to be a conserved trait in proteobacterial methanotrophs; indeed, plcP is found in all proteobacterial methanotroph genomes, and plcP transcripts from methanotrophs are readily detectable in metatranscriptomics data sets. Together, our study provides new insights into the adaptation to P limitation in this ecologically important group of bacteria.
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74
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Chetri JK, Reddy KR, Green SJ. Use of methanotrophically activated biochar in novel biogeochemical cover system for carbon sequestration: Microbial characterization. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 821:153429. [PMID: 35101512 DOI: 10.1016/j.scitotenv.2022.153429] [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: 11/11/2021] [Revised: 01/05/2022] [Accepted: 01/22/2022] [Indexed: 06/14/2023]
Abstract
Biochar-amended soils have been explored to enhance microbial methane (CH4) oxidation in landfill cover systems. Recently, research priorities have expanded to include the mitigation of other components of landfill gas such as carbon dioxide (CO2) and hydrogen sulfide (H2S) along with CH4. In this study, column tests were performed to simulate the newly proposed biogeochemical cover systems, which incorporate biochar-amended soil for CH4 oxidation and basic oxygen furnace (BOF) slag for CO2 and H2S mitigation, to evaluate the effect of cover configuration on microbial CH4 oxidation and community composition. Biogeochemical covers included a biochar-amended soil (10% w/w), and methanotroph-enriched activated biochar amended soil (5% or 10% w/w) as a biocover layer or CH4 oxidation layer. The primary outcome measures of interest were CH4 oxidation rates and the structure and abundance of methane-oxidation bacteria in the covers. All column reactors were active in CH4 oxidation, but columns containing activated biochar-amended soils had higher CH4 oxidation rates (133 to 143 μg CH4 g-1 day-1) than those containing non-activated biochar-amended soil (50 μg CH4 g-1 day-1) and no-biochar soil or control soil (43 μg CH4 g-1 day-1). All treatments showed significant increases in the relative abundance of methanotrophs from an average relative abundance of 5.6% before incubation to a maximum of 45% following incubation. In activated biochar, the abundance of Type II methanotrophs, primarily Methylocystis and Methylosinus, was greater than that of Type I methanotrophs (Methylobacter) due to which activated biochar-amended soils also showed higher abundance of Type II methanotrophs. Overall, biogeochemical cover profiles showed promising potential for CH4 oxidation without any adverse effect on microbial community composition and methane oxidation. Biochar activation led to an alteration of the dominant methanotrophic communities and increased CH4 oxidation.
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Affiliation(s)
- Jyoti K Chetri
- University of Illinois at Chicago, Department of Civil, Materials, and Environmental Engineering, 842 West Taylor Street, Chicago, IL 60607, USA.
| | - Krishna R Reddy
- University of Illinois at Chicago, Department of Civil, Materials, and Environmental Engineering, 842 West Taylor Street, Chicago, IL 60607, USA.
| | - Stefan J Green
- Genomics and Microbiome Core Facility, Rush University Medical Center, 1653 W. Congress Parkway, Jelke Building, Room 444, Chicago, IL 60612, USA.
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75
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Taxonomic and functional trait-based approaches suggest that aerobic and anaerobic soil microorganisms allow the natural attenuation of oil from natural seeps. Sci Rep 2022; 12:7245. [PMID: 35508504 PMCID: PMC9068923 DOI: 10.1038/s41598-022-10850-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 03/31/2022] [Indexed: 12/02/2022] Open
Abstract
Natural attenuation, involving microbial adaptation, helps mitigating the effect of oil contamination of surface soils. We hypothesized that in soils under fluctuating conditions and receiving oil from seeps, aerobic and anaerobic bacteria as well as fungi could coexist to efficiently degrade hydrocarbons and prevent the spread of pollution. Microbial community diversity was studied in soil longitudinal and depth gradients contaminated with petroleum seeps for at least a century. Hydrocarbon contamination was high just next to the petroleum seeps but this level drastically lowered from 2 m distance and beyond. Fungal abundance and alpha-diversity indices were constant along the gradients. Bacterial abundance was constant but alpha-diversity indices were lower next to the oil seeps. Hydrocarbon contamination was the main driver of microbial community assemblage. 281 bacterial OTUs were identified as indicator taxa, tolerant to hydrocarbon, potentially involved in hydrocarbon-degradation or benefiting from the degradation by-products. These taxa belonging to lineages of aerobic and anaerobic bacteria, have specific functional traits indicating the development of a complex community adapted to the biodegradation of petroleum hydrocarbons and to fluctuating conditions. Fungi are less impacted by oil contamination but few taxa should contribute to the metabolic complementary within the microbial consortia forming an efficient barrier against petroleum dissemination.
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76
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Ouboter HT, Berben T, Berger S, Jetten MSM, Sleutels T, Ter Heijne A, Welte CU. Methane-Dependent Extracellular Electron Transfer at the Bioanode by the Anaerobic Archaeal Methanotroph " Candidatus Methanoperedens". Front Microbiol 2022; 13:820989. [PMID: 35495668 PMCID: PMC9039326 DOI: 10.3389/fmicb.2022.820989] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 03/10/2022] [Indexed: 12/11/2022] Open
Abstract
Anaerobic methanotrophic (ANME) archaea have recently been reported to be capable of using insoluble extracellular electron acceptors via extracellular electron transfer (EET). In this study, we investigated EET by a microbial community dominated by "Candidatus Methanoperedens" archaea at the anode of a bioelectrochemical system (BES) poised at 0 V vs. standard hydrogen electrode (SHE), in this way measuring current as a direct proxy of EET by this community. After inoculation of the BES, the maximum current density was 274 mA m-2 (stable current up to 39 mA m-2). Concomitant conversion of 13CH4 into 13CO2 demonstrated that current production was methane-dependent, with 38% of the current attributed directly to methane supply. Based on the current production and methane uptake in a closed system, the Coulombic efficiency was about 17%. Polarization curves demonstrated that the current was limited by microbial activity at potentials above 0 V. The metatranscriptome of the inoculum was mined for the expression of c-type cytochromes potentially used for EET, which led to the identification of several multiheme c-type cytochrome-encoding genes among the most abundant transcripts in "Ca. Methanoperedens." Our study provides strong indications of EET in ANME archaea and describes a system in which ANME-mediated EET can be investigated under laboratory conditions, which provides new research opportunities for mechanistic studies and possibly the generation of axenic ANME cultures.
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Affiliation(s)
- Heleen T Ouboter
- Institute for Water and Wetland Research, Department of Microbiology, Radboud University, Nijmegen, Netherlands
| | - Tom Berben
- Institute for Water and Wetland Research, Department of Microbiology, Radboud University, Nijmegen, Netherlands
| | - Stefanie Berger
- Institute for Water and Wetland Research, Department of Microbiology, Radboud University, Nijmegen, Netherlands
| | - Mike S M Jetten
- Institute for Water and Wetland Research, Department of Microbiology, Radboud University, Nijmegen, Netherlands
| | - Tom Sleutels
- Wetsus, European Center of Excellence for Sustainable Water Technology, Leeuwarden, Netherlands.,Faculty of Science and Engineering, University of Groningen, Groningen, Netherlands
| | | | - Cornelia U Welte
- Institute for Water and Wetland Research, Department of Microbiology, Radboud University, Nijmegen, Netherlands
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77
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Cai Y, Yun J, Jia Z. Phylogeny and Metabolic Potential of the Methanotrophic Lineage MO3 in Beijerinckiaceae from the Paddy Soil through Metagenome-Assembled Genome Reconstruction. Microorganisms 2022; 10:microorganisms10050955. [PMID: 35630399 PMCID: PMC9145241 DOI: 10.3390/microorganisms10050955] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 04/22/2022] [Accepted: 04/29/2022] [Indexed: 01/27/2023] Open
Abstract
Although the study of aerobic methane-oxidizing bacteria (MOB, methanotrophs) has been carried out for more than a hundred years, there are many uncultivated methanotrophic lineages whose metabolism is largely unknown. Here, we reconstructed a nearly complete genome of a Beijerinckiaceae methanotroph from the enrichment of paddy soil by using nitrogen-free M2 medium. The methanotroph labeled as MO3_YZ.1 had a size of 3.83 Mb, GC content of 65.6%, and 3442 gene-coding regions. Based on phylogeny of pmoA gene and genome and the genomic average nucleotide identity, we confirmed its affiliation to the MO3 lineage and a close relationship to Methylocapsa. MO3_YZ.1 contained mxaF- and xoxF-type methanol dehydrogenase. MO3_YZ.1 used the serine cycle to assimilate carbon and regenerated glyoxylate through the glyoxylate shunt as it contained isocitrate lyase and complete tricarboxylic acid cycle-coding genes. The ethylmalonyl-CoA pathway and Calvin–Benson–Bassham cycle were incomplete in MO3_YZ.1. Three acetate utilization enzyme-coding genes were identified, suggesting its potential ability to utilize acetate. The presence of genes for N2 fixation, sulfur transformation, and poly-β-hydroxybutyrate synthesis enable its survival in heterogeneous habitats with fluctuating supplies of carbon, nitrogen, and sulfur.
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Affiliation(s)
- Yuanfeng Cai
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
- Correspondence: (Y.C.); (Z.J.); Tel.: +86-25-8688-1850 (Y.C.); +86-25-8688-1311 (Z.J.)
| | - Juanli Yun
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China;
| | - Zhongjun Jia
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
- Correspondence: (Y.C.); (Z.J.); Tel.: +86-25-8688-1850 (Y.C.); +86-25-8688-1311 (Z.J.)
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78
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Soils and sediments host Thermoplasmata archaea encoding novel copper membrane monooxygenases (CuMMOs). THE ISME JOURNAL 2022; 16:1348-1362. [PMID: 34987183 PMCID: PMC9038741 DOI: 10.1038/s41396-021-01177-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 12/02/2021] [Accepted: 12/10/2021] [Indexed: 01/22/2023]
Abstract
Copper membrane monooxygenases (CuMMOs) play critical roles in the global carbon and nitrogen cycles. Organisms harboring these enzymes perform the first, and rate limiting, step in aerobic oxidation of ammonia, methane, or other simple hydrocarbons. Within archaea, only organisms in the order Nitrososphaerales (Thaumarchaeota) encode CuMMOs, which function exclusively as ammonia monooxygenases. From grassland and hillslope soils and aquifer sediments, we identified 20 genomes from distinct archaeal species encoding divergent CuMMO sequences. These archaea are phylogenetically clustered in a previously unnamed Thermoplasmatota order, herein named the Ca. Angelarchaeales. The CuMMO proteins in Ca. Angelarchaeales are more similar in structure to those in Nitrososphaerales than those of bacteria, and contain all functional residues required for general monooxygenase activity. Ca. Angelarchaeales genomes are significantly enriched in blue copper proteins (BCPs) relative to sibling lineages, including plastocyanin-like electron carriers and divergent nitrite reductase-like (nirK) 2-domain cupredoxin proteins co-located with electron transport machinery. Ca. Angelarchaeales also encode significant capacity for peptide/amino acid uptake and degradation and share numerous electron transport mechanisms with the Nitrososphaerales. Ca. Angelarchaeales are detected at high relative abundance in some of the environments where their genomes originated from. While the exact substrate specificities of the novel CuMMOs identified here have yet to be determined, activity on ammonia is possible given their metabolic and ecological context. The identification of an archaeal CuMMO outside of the Nitrososphaerales significantly expands the known diversity of CuMMO enzymes in archaea and suggests previously unaccounted organisms contribute to critical global nitrogen and/or carbon cycling functions.
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79
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Steinsdóttir HGR, Gómez Ramírez E, Mhatre S, Schauberger C, Bertagnolli AD, Pratte ZA, Stewart FJ, Thamdrup B, Bristow LA. Anaerobic methane oxidation in a coastal oxygen minimum zone: spatial and temporal dynamics. Environ Microbiol 2022; 24:2361-2379. [PMID: 35415879 PMCID: PMC9323439 DOI: 10.1111/1462-2920.16003] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 04/05/2022] [Accepted: 04/05/2022] [Indexed: 11/28/2022]
Abstract
Coastal waters are a major source of marine methane to the atmosphere. Particularly high concentrations of this potent greenhouse gas are found in anoxic waters, but it remains unclear if and to what extent anaerobic methanotrophs mitigate the methane flux. Here we investigate the long-term dynamics in methanotrophic activity and the methanotroph community in the coastal oxygen minimum zone (OMZ) of Golfo Dulce, Costa Rica, combining biogeochemical analyses, experimental incubations, and 16S rRNA gene sequencing over three consecutive years. Our results demonstrate a stable redox zonation across the years with high concentrations of methane (up to 1.7 μmol L-1 ) in anoxic bottom waters. However, we also measured high activities of anaerobic methane oxidation in the OMZ core (rate constant, k, averaging 30 yr-1 in 2018 and 8 yr-1 in 2019-2020). The OPU3 and Deep Sea-1 clades of the Methylococcales were implicated as conveyors of the activity, peaking in relative abundance 5-25 m below the oxic-anoxic interface and in the deep anoxic water, respectively. Although their genetic capacity for anaerobic methane oxidation remains unexplored, their sustained high relative abundance indicates an adaptation of these clades to the anoxic, methane-rich OMZ environment, allowing them to play major roles in mitigating methane fluxes. This article is protected by copyright. All rights reserved.
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Affiliation(s)
| | - Eddy Gómez Ramírez
- CIMAR, Universidad de Costa Rica, San Pedro de Montes de Oca, Costa Rica
| | - Snehit Mhatre
- Department of Biology, University of Southern Denmark, Odense, Denmark
| | | | - Anthony D Bertagnolli
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, Montana
| | - Zoe A Pratte
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, Montana
| | - Frank J Stewart
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, Montana.,School of Biological Sciences, Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, GA
| | - Bo Thamdrup
- Department of Biology, University of Southern Denmark, Odense, Denmark
| | - Laura A Bristow
- Department of Biology, University of Southern Denmark, Odense, Denmark
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80
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Yang Y, Chen J, Pratscher J, Xie S. DNA-SIP reveals an overlooked methanotroph, Crenothrix sp., involved in methane consumption in shallow lake sediments. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 814:152742. [PMID: 34974014 DOI: 10.1016/j.scitotenv.2021.152742] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 12/22/2021] [Accepted: 12/24/2021] [Indexed: 06/14/2023]
Abstract
Methanotrophs are the main consumers of methane produced in lake sediments. In shallow lakes suffering from eutrophication, methanogenesis is accelerated by the excess organic carbon input, and thus methanotrophs play a key role in regulating this methane flux as well as carbon cycling. Here, we applied nucleic acid stable isotope probing (SIP) to investigate the active methanotrophic microbial community in sediments of several shallow lakes affected by eutrophication. Our results showed that an active methanotrophic community dominated by gamma-proteobacterial methanotrophs, as well as abundant beta-proteobacterial methanol-utilizers, was involved in methane-derived carbon assimilation. Crenothrix, a filamentous methanotroph, was found to be a key methane consumer in all studied lakes. The ecological role of Crenothrix in lacustrine ecosystems is so far poorly understood, with only limited information on its existence in the water column of stratified lakes. Our results provide a novel ecological insight into this group by revealing a wide distribution of Crenothrix in lake sediments. The active methane assimilation by Crenothrix also suggested that it might represent a so far overlooked but crucial biological sink of methane in shallow lakes.
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Affiliation(s)
- Yuyin Yang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China; The Lyell Centre, School of Energy, Geoscience, Infrastructure and Society, Heriot-Watt University, Research Avenue South, Edinburgh EH14 4AP, UK
| | - Jianfei Chen
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Jennifer Pratscher
- The Lyell Centre, School of Energy, Geoscience, Infrastructure and Society, Heriot-Watt University, Research Avenue South, Edinburgh EH14 4AP, UK
| | - Shuguang Xie
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
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81
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Hudson JM, Michaud AB, Emerson D, Chin YP. Spatial distribution and biogeochemistry of redox active species in arctic sedimentary porewaters and seeps. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2022; 24:426-438. [PMID: 35170586 DOI: 10.1039/d1em00505g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Redox active species in Arctic lacustrine sediments play an important, regulatory role in the carbon cycle, yet there is little information on their spatial distribution, abundance, and oxidation states. Here, we use voltammetric microelectrodes to quantify the in situ concentrations of redox-active species at high vertical resolution (mm to cm) in the benthic porewaters of an oligotrophic Arctic lake (Toolik Lake, AK, USA). Mn(II), Fe(II), O2, and Fe(III)-organic complexes were detected as the major redox-active species in these porewaters, indicating both Fe(II) oxidation and reductive dissolution of Fe(III) and Mn(IV) minerals. We observed significant spatial heterogeneity in their abundance and distribution as a function of both location within the lake and depth. Microbiological analyses and solid phase Fe(III) measurements were performed in one of the Toolik Lake cores to determine the relationship between biogeochemical redox gradients and microbial communities. Our data reveal iron cycling involving both oxidizing (FeOB) and reducing (FeRB) bacteria. Additionally, we profiled a large microbial iron mat in a tundra seep adjacent to an Arctic stream (Oksrukuyik Creek) where we observed Fe(II) and soluble Fe(III) in a highly reducing environment. The variable distribution of redox-active substances at all the sites yields insights into the nature and distribution of the important terminal electron acceptors in both lacustrine and tundra environments capable of exerting significant influences on the carbon cycle.
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Affiliation(s)
- Jeffrey M Hudson
- Department of Civil and Environmental Engineering, University of Delaware, Newark, Delaware 19716, USA.
| | | | - David Emerson
- Bigelow Laboratory for Ocean Sciences, East Boothbay, Maine, 04544, USA
| | - Yu-Ping Chin
- Department of Civil and Environmental Engineering, University of Delaware, Newark, Delaware 19716, USA.
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82
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Roldán DM, Carrizo D, Sánchez-García L, Menes RJ. Diversity and Effect of Increasing Temperature on the Activity of Methanotrophs in Sediments of Fildes Peninsula Freshwater Lakes, King George Island, Antarctica. Front Microbiol 2022; 13:822552. [PMID: 35369426 PMCID: PMC8969513 DOI: 10.3389/fmicb.2022.822552] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 02/07/2022] [Indexed: 01/04/2023] Open
Abstract
Global warming has a strong impact on polar regions. Particularly, the Antarctic Peninsula and nearby islands have experienced a marked warming trend in the past 50 years. Therefore, higher methane (CH4) emissions from this area could be expected in the future. Since mitigation of these emissions can be carried out by microbial oxidation, understanding this biological process is crucial since to our knowledge, no related studies have been performed in this area before. In this work, the aerobic CH4 oxidation potential of five freshwater lake sediments of Fildes Peninsula (King George Island, South Shetland Islands) was determined with values from 0.07 to 10 μmol CH4 gdw–1 day–1 and revealed up to 100-fold increase in temperature gradients (5, 10, 15, and 20°C). The structure and diversity of the bacterial community in the sediments were analyzed by next-generation sequencing (Illumina MiSeq) of 16S rRNA and pmoA genes. A total of 4,836 ASVs were identified being Proteobacteria, Actinobacteriota, Acidobacteriota, and Bacteroidota the most abundant phyla. The analysis of the pmoA gene identified 200 ASVs of methanotrophs, being Methylobacter Clade 2 (Type I, family Methylococcaceae) the main responsible of the aerobic CH4 oxidation. Moreover, both approaches revealed the presence of methanotrophs of the classes Gammaproteobacteria (families Methylococcaceae and Crenotrichaceae), Alphaproteobacteria (family Methylocystaceae), Verrucomicrobia (family Methylacidiphilaceae), and the candidate phylum of anaerobic methanotrophs Methylomirabilota. In addition, bacterial phospholipid fatty acids (PLFA) biomarkers were studied as a proxy for aerobic methane-oxidizing bacteria and confirmed these results. Methanotrophic bacterial diversity was significantly correlated with pH. In conclusion, our findings suggest that aerobic methanotrophs could mitigate in situ CH4 emissions in a future scenario with higher temperatures in this climate-sensitive area. This study provides new insights into the diversity of methanotrophs, as well as the influence of temperature on the CH4 oxidation potential in sediments of freshwater lakes in polar regions of the southern hemisphere.
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Affiliation(s)
- Diego M. Roldán
- Laboratorio de Ecología Microbiana Medioambiental, Facultad de Química, Universidad de la República, Montevideo, Uruguay
- Laboratorio de Microbiología, Unidad Asociada del Instituto de Química Biológica, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Daniel Carrizo
- Centro de Astrobiología, Consejo Superior de Investigaciones Científicas-Instituto Nacional de Técnica Aeroespacial (CSIC-INTA), Madrid, Spain
| | - Laura Sánchez-García
- Centro de Astrobiología, Consejo Superior de Investigaciones Científicas-Instituto Nacional de Técnica Aeroespacial (CSIC-INTA), Madrid, Spain
| | - Rodolfo Javier Menes
- Laboratorio de Ecología Microbiana Medioambiental, Facultad de Química, Universidad de la República, Montevideo, Uruguay
- Laboratorio de Microbiología, Unidad Asociada del Instituto de Química Biológica, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
- *Correspondence: Rodolfo Javier Menes,
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83
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Variable Inhibition of Nitrous Oxide Reduction in Denitrifying Bacteria by Different Forms of Methanobactin. Appl Environ Microbiol 2022; 88:e0234621. [PMID: 35285718 DOI: 10.1128/aem.02346-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Aerobic methanotrophic activity is highly dependent on copper availability, and methanotrophs have developed multiple strategies to collect copper. Specifically, when copper is limiting (ambient concentrations less than 1 μM), some methanotrophs produce and secret a small modified peptide (less than 1,300 Da) termed methanobactin (MB) that binds copper with high affinity. As MB is secreted into the environment, other microbes that require copper for their metabolism may be inhibited as MB may make copper unavailable; e.g., inhibition of denitrifiers as complete conversion nitrate to dinitrogen involves multiple enzymes, some of which are copper-dependent. Of key concern is inhibition of the copper-dependent nitrous oxide reductase (NosZ), the only known enzyme capable of converting nitrous oxide (N2O) to dinitrogen. Herein, we show that different forms of MB differentially affect copper uptake and N2O reduction by Pseudomonas stutzeri strain DCP-Ps1 (that expresses clade I NosZ) and Dechloromonas aromatica strain RCB (that expresses clade II NosZ). Specifically, in the presence of MB from Methylocystis sp. strain SB2 (SB2-MB), copper uptake and nosZ expression were more significantly reduced than in the presence of MB from Methylosinus trichosporium OB3b (OB3b-MB). Further, N2O accumulation increased more significantly for both P. stutzeri strain DCP-Ps1 and D. aromatica strain RCB in the presence of SB2-MB versus OB3b-MB. These data illustrate that copper competition between methanotrophs and denitrifying bacteria can be significant and that the extent of such competition is dependent on the form of MB that methanotrophs produce. IMPORTANCE Herein, it was demonstrated that the different forms of methanobactin differentially enhance N2O emissions from Pseudomonas stutzeri strain DCP-Ps1 (harboring clade I nitrous oxide reductase) and Dechloromonas aromatica strain RCB (harboring clade II nitrous oxide reductase). This work contributes to our understanding of how aerobic methanotrophs compete with denitrifiers for the copper uptake and also suggests how MBs prevent copper collection by denitrifiers, thus downregulating expression of nitrous oxide reductase. This study provides critical information for enhanced understanding of microbe-microbe interactions that are important for the development of better predictive models of net greenhouse gas emissions (i.e., methane and nitrous oxide) that are significantly controlled by microbial activity.
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84
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Qian L, Yu X, Zhou J, Gu H, Ding J, Peng Y, He Q, Tian Y, Liu J, Wang S, Wang C, Shu L, Yan Q, He J, Liu G, Tu Q, He Z. MCycDB: a curated database for comprehensively profiling methane cycling processes of environmental microbiomes. Mol Ecol Resour 2022; 22:1803-1823. [DOI: 10.1111/1755-0998.13589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 12/24/2021] [Accepted: 01/17/2022] [Indexed: 11/30/2022]
Affiliation(s)
- Lu Qian
- Environmental Microbiomics Research Center School of Environmental Science and Engineering Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) Sun Yat‐sen University Guangzhou 510006 China
| | - Xiaoli Yu
- Environmental Microbiomics Research Center School of Environmental Science and Engineering Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) Sun Yat‐sen University Guangzhou 510006 China
| | - Jiayin Zhou
- Institute of Marine Science and Technology Shandong University Qingdao 266237 China
| | - Hang Gu
- Environmental Microbiomics Research Center School of Environmental Science and Engineering Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) Sun Yat‐sen University Guangzhou 510006 China
| | - Jijuan Ding
- Environmental Microbiomics Research Center School of Environmental Science and Engineering Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) Sun Yat‐sen University Guangzhou 510006 China
| | - Yisheng Peng
- Environmental Microbiomics Research Center School of Environmental Science and Engineering Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) Sun Yat‐sen University Guangzhou 510006 China
| | - Qiang He
- Department of Civil and Environmental Engineering the University of Tennessee Knoxville TN 37996 USA
| | - Yun Tian
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems School of Life Sciences Xiamen University Xiamen 361005 China
| | - Jihua Liu
- Institute of Marine Science and Technology Shandong University Qingdao 266237 China
| | - Shanquan Wang
- Environmental Microbiomics Research Center School of Environmental Science and Engineering Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) Sun Yat‐sen University Guangzhou 510006 China
| | - Cheng Wang
- Environmental Microbiomics Research Center School of Environmental Science and Engineering Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) Sun Yat‐sen University Guangzhou 510006 China
| | - Longfei Shu
- Environmental Microbiomics Research Center School of Environmental Science and Engineering Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) Sun Yat‐sen University Guangzhou 510006 China
| | - Qingyun Yan
- Environmental Microbiomics Research Center School of Environmental Science and Engineering Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) Sun Yat‐sen University Guangzhou 510006 China
| | - Jianguo He
- School of Life Science Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) Sun Yat‐sen University Guangzhou 510006 China
| | - Guangli Liu
- Environmental Microbiomics Research Center School of Environmental Science and Engineering Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) Sun Yat‐sen University Guangzhou 510006 China
| | - Qichao Tu
- Institute of Marine Science and Technology Shandong University Qingdao 266237 China
| | - Zhili He
- Environmental Microbiomics Research Center School of Environmental Science and Engineering Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) Sun Yat‐sen University Guangzhou 510006 China
- College of Agronomy Hunan Agricultural University Changsha 410128 China
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85
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Altshuler I, Raymond-Bouchard I, Magnuson E, Tremblay J, Greer CW, Whyte LG. Unique high Arctic methane metabolizing community revealed through in situ 13CH 4-DNA-SIP enrichment in concert with genome binning. Sci Rep 2022; 12:1160. [PMID: 35064149 PMCID: PMC8782848 DOI: 10.1038/s41598-021-04486-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 11/30/2021] [Indexed: 12/15/2022] Open
Abstract
Greenhouse gas (GHG) emissions from Arctic permafrost soils create a positive feedback loop of climate warming and further GHG emissions. Active methane uptake in these soils can reduce the impact of GHG on future Arctic warming potential. Aerobic methane oxidizers are thought to be responsible for this apparent methane sink, though Arctic representatives of these organisms have resisted culturing efforts. Here, we first used in situ gas flux measurements and qPCR to identify relative methane sink hotspots at a high Arctic cytosol site, we then labeled the active microbiome in situ using DNA Stable Isotope Probing (SIP) with heavy 13CH4 (at 100 ppm and 1000 ppm). This was followed by amplicon and metagenome sequencing to identify active organisms involved in CH4 metabolism in these high Arctic cryosols. Sequencing of 13C-labeled pmoA genes demonstrated that type II methanotrophs (Methylocapsa) were overall the dominant active methane oxidizers in these mineral cryosols, while type I methanotrophs (Methylomarinovum) were only detected in the 100 ppm SIP treatment. From the SIP-13C-labeled DNA, we retrieved nine high to intermediate quality metagenome-assembled genomes (MAGs) belonging to the Proteobacteria, Gemmatimonadetes, and Chloroflexi, with three of these MAGs containing genes associated with methanotrophy. A novel Chloroflexi MAG contained a mmoX gene along with other methane oxidation pathway genes, identifying it as a potential uncultured methane oxidizer. This MAG also contained genes for copper import, synthesis of biopolymers, mercury detoxification, and ammonia uptake, indicating that this bacterium is strongly adapted to conditions in active layer permafrost and providing new insights into methane biogeochemical cycling. In addition, Betaproteobacterial MAGs were also identified as potential cross-feeders with methanotrophs in these Arctic cryosols. Overall, in situ SIP labeling combined with metagenomics and genome binning demonstrated to be a useful tool for discovering and characterizing novel organisms related to specific microbial functions or biogeochemical cycles of interest. Our findings reveal a unique and active Arctic cryosol microbial community potentially involved in CH4 cycling.
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Affiliation(s)
- Ianina Altshuler
- Department of Natural Resource Sciences, McGill University, 21,111 Lakeshore Rd., Ste. Anne de Bellevue, QC, H9X 3V9, Canada.
- Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences NMBU, Universitetstunet 3, 1430, Ås, Norway.
| | - Isabelle Raymond-Bouchard
- Department of Natural Resource Sciences, McGill University, 21,111 Lakeshore Rd., Ste. Anne de Bellevue, QC, H9X 3V9, Canada
| | - Elisse Magnuson
- Department of Natural Resource Sciences, McGill University, 21,111 Lakeshore Rd., Ste. Anne de Bellevue, QC, H9X 3V9, Canada
| | - Julien Tremblay
- Energy, Mining and Environment Research Centre, National Research Council of Canada, 6100 Royalmount Ave., Montreal, QC, H4P 2R2, Canada
| | - Charles W Greer
- Department of Natural Resource Sciences, McGill University, 21,111 Lakeshore Rd., Ste. Anne de Bellevue, QC, H9X 3V9, Canada
- Energy, Mining and Environment Research Centre, National Research Council of Canada, 6100 Royalmount Ave., Montreal, QC, H4P 2R2, Canada
| | - Lyle G Whyte
- Department of Natural Resource Sciences, McGill University, 21,111 Lakeshore Rd., Ste. Anne de Bellevue, QC, H9X 3V9, Canada
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86
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Clark DR, McKew BA, Binley A, Heppell CM, Whitby C, Trimmer M. Hydrological properties predict the composition of microbial communities cycling methane and nitrogen in rivers. ISME COMMUNICATIONS 2022; 2:5. [PMID: 37938696 PMCID: PMC9723640 DOI: 10.1038/s43705-022-00087-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 12/18/2021] [Accepted: 12/23/2021] [Indexed: 11/09/2023]
Abstract
Sediment microbial communities drive the biogeochemical cycles that make rivers globally important sources and sinks of carbon (C) and nitrogen (N). The structure of these communities is strongly determined by the local physico-chemical environment. However, we currently lack an understanding of the factors that determine microbial community structures at the catchment scale. Here, we show that the contribution of groundwater to total river flow (quantified as base flow index; BFI) predicts the structure and diversity of the different microbial functional groups that cycle N and C across nine UK rivers, spanning a geological BFI gradient from 0.23 (clay sediment) to 0.95 (chalk gravel sediment). Furthermore, the GC-content (percentage of guanine-cytosine bases in a DNA sequence) and codon-usage bias of ammonia monooxygenase DNA sequences, and the hydrophobicity and net-charge of the corresponding amino acid sequences, were all strongly correlated with BFI, likely reflecting physiological adaptations to different riverbed sediment structure along the BFI gradient. Our results offer an opportunity to overcome the "paradox of scales" that has seen microbial ecologists focus on small- rather than large-scale environmental variables, enabling us to scale-up our understanding of microbial biogeochemistry to the catchment and beyond.
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Affiliation(s)
- Dave R Clark
- School of Life Sciences, University of Essex, Wivenhoe Park, Colchester, Essex, CO4 3SQ, UK.
- Institute for Analytics and Data Science, University of Essex, Wivenhoe Park, Colchester, Essex, CO4 3SQ, UK.
| | - Boyd A McKew
- School of Life Sciences, University of Essex, Wivenhoe Park, Colchester, Essex, CO4 3SQ, UK
| | - Andrew Binley
- Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ, UK
| | - Catherine M Heppell
- School of Geography, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
| | - Corinne Whitby
- School of Life Sciences, University of Essex, Wivenhoe Park, Colchester, Essex, CO4 3SQ, UK
| | - Mark Trimmer
- School of Biological and Behavioural Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
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87
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Genome Sequence of a Thermoacidophilic Methanotroph Belonging to the Verrucomicrobiota Phylum from Geothermal Hot Springs in Yellowstone National Park: A Metagenomic Assembly and Reconstruction. Microorganisms 2022; 10:microorganisms10010142. [PMID: 35056591 PMCID: PMC8779874 DOI: 10.3390/microorganisms10010142] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 12/23/2021] [Accepted: 01/07/2022] [Indexed: 02/04/2023] Open
Abstract
Verrucomicrobiotal methanotrophs are thermoacidophilic methane oxidizers that have been isolated from volcanic and geothermal regions of the world. We used a metagenomic approach that entailed obtaining the whole genome sequence of a verrucomicrobiotal methanotroph from a microbial consortium enriched from samples obtained from Nymph Lake (89.9 °C, pH 2.73) in Yellowstone National Park in the USA. To identify and reconstruct the verrucomicrobiotal genome from Illumina NovaSeq 6000 sequencing data, we constructed a bioinformatic pipeline with various combinations of de novo assembly, alignment, and binning algorithms. Based on the marker gene (pmoA), we identified and assembled the Candidatus Methylacidiphilum sp. YNP IV genome (2.47 Mbp, 2392 ORF, and 41.26% GC content). In a comparison of average nucleotide identity between Ca. Methylacidiphilum sp. YNP IV and Ca. Methylacidiphilum fumariolicum SolV, its closest 16S rRNA gene sequence relative, is lower than 95%, suggesting that Ca. Methylacidiphilum sp. YNP IV can be regarded as a different species. The Ca. Methylacidiphilum sp. YNP IV genome assembly showed most of the key genes for methane metabolism, the CBB pathway for CO2 fixation, nitrogen fixation and assimilation, hydrogenases, and rare earth elements transporter, as well as defense mechanisms. The assembly and reconstruction of a thermoacidophilic methanotroph belonging to the Verrucomicrobiota phylum from a geothermal environment adds further evidence and knowledge concerning the diversity of biological methane oxidation and on the adaptation of this geochemically relevant reaction in extreme environments.
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88
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Kulkarni PP, Chavan SB, Deshpande MS, Sagotra D, Kumbhar PS, Ghosalkar AR. Enrichment of Methylocystis dominant mixed culture from rice field for PHB production. J Biotechnol 2022; 343:62-70. [PMID: 34838616 DOI: 10.1016/j.jbiotec.2021.11.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 11/16/2021] [Accepted: 11/20/2021] [Indexed: 11/16/2022]
Abstract
Presence of methanotrophs in diverse environmental habitats helps to reduce emissions of greenhouse gas like methane. Isolation and culture of undiscovered wealth of methanotrophic organisms can help in exploitation of these organisms in value added products. The present study focuses on the enrichment of methanotroph dominated mixed microbial community by use of three stage strategy of revival, proliferation, and segregation. During the enrichment process amplicon sequencing of 16 s rRNA V3-V4 region showed relative abundance of mixed culture comprising single methanotrophic species of Methylocystis genus (88.92%) along with only three other species. Methylocystis dominant mixed culture (MMI-11) was observed to produce polyhydroxyalkanoates (PHA). During studies to identify favourable culture conditions, nitrate was found to be preferred nitrogen source for growth and PHA production. Cell growth ability to produce PHA was also evaluated at 14 L fermentor by supplying gas using continuous bubbling and through pressurization in the headspace. The mixed methanotrophic culture was found to accumulate maximum of 22.20% polyhydroxybutyrate (PHB) under nitrate limited condition. The molecular weight of PHB was found to be 2.221 × 105 g mol-1 with polydispersity of 1.82.
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Affiliation(s)
- Pranav P Kulkarni
- Department of Technology, Savitribai Phule Pune University, Pune, India; Praj Matrix - R&D Centre, division of Praj Industries Limited, Urawade, Pune, India
| | - Sambhaji B Chavan
- Praj Matrix - R&D Centre, division of Praj Industries Limited, Urawade, Pune, India
| | - Mandar S Deshpande
- Praj Matrix - R&D Centre, division of Praj Industries Limited, Urawade, Pune, India
| | - Dhanishta Sagotra
- Department of Technology, Savitribai Phule Pune University, Pune, India
| | - Pramod S Kumbhar
- Praj Matrix - R&D Centre, division of Praj Industries Limited, Urawade, Pune, India
| | - Anand R Ghosalkar
- Department of Technology, Savitribai Phule Pune University, Pune, India; Praj Matrix - R&D Centre, division of Praj Industries Limited, Urawade, Pune, India.
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89
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Cupples AM, Thelusmond JR. Predicting the occurrence of monooxygenases and their associated phylotypes in soil microcosms. METHODS IN MICROBIOLOGY 2021; 193:106401. [PMID: 34973287 DOI: 10.1016/j.mimet.2021.106401] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 12/23/2021] [Accepted: 12/23/2021] [Indexed: 10/19/2022]
Abstract
Cometabolic oxidation involves the oxidation of chemicals often by monooxygenases or dioxygenases and can be a removal process for environmental contaminants such as trichloroethene (TCE) or 1,4-dioxane. Information on the occurrence of these genes and their associated microorganisms in environmental samples has the potential to enhance our understanding of contaminant removal. The overall aims were to 1) ascertain which genes encoding for monooxygenases (from methanotrophs, ammonia oxidizing bacteria and toluene/phenol oxidizers) and other key enzymes are present in soil microcosms and 2) determine which phylotypes are associated with those genes. The approach involved a predictive tool called PICRUSt2 and 16S rRNA gene amplicon datasets from two previous soil microcosm studies. The following targets from the KEGG database were examined: pmo/amo, mmo, dmp/pox/tomA, tmo/tbu/tou, bssABC (and downstream genes), tod, xylM, xylA, gst, dhaA, catE, dbfA1, dbfA2 and phenol 2-monooxygenase. A large number of phylotypes were associated with pmo/amo, while mmo was linked to only five. Several phylotypes were associated with both pmo/amo and mmo. The most dominant microorganism predicted for mmoX was Mycobacterium (also predicted for pmo/amo). A large number of phylotypes were associated with all six genes from the dmp/pox/tomA KEGG group. The taxonomic associations predicted for the tmo/tbu/tou KEGG group were more limited. In both datasets, Geobacter was a key phylotype for benzylsuccinate synthase. The dioxygenase-mediated toluene degradation pathway encoded by todC1C2BA was largely absent, as were the genes (xylM, xylA) encoding for xylene monooxygenase. All other genes investigated were predicted to be present and were associated with a number of microorganisms. Overall, the analysis predicted the genes encoding for sMMO (mmo), T3MO/T3MO/ToMO (tmo/tbu/tou) and benzylsuccinate synthase (bssABC) are present for a limited number of phylotypes compared to those encoding for pMMO/AMO (pmo/amo) and phenol monooxygenase/T2MO (dmp/poxA/tomA). These findings suggest in soils contaminant removal via pMMO/AMO or phenol monooxygenase/T2MO may be common because of the occurrence of these enzymes with a large number of phylotypes.
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Affiliation(s)
- Alison M Cupples
- Department of Civil and Environmental Engineering, Michigan State University, East Lansing, MI, USA.
| | - Jean-Rene Thelusmond
- Department of Civil and Environmental Engineering, Michigan State University, East Lansing, MI, USA
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90
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Adapting Macroecology to Microbiology: Using Occupancy Modeling To Assess Functional Profiles across Metagenomes. mSystems 2021; 6:e0079021. [PMID: 34874772 PMCID: PMC8651082 DOI: 10.1128/msystems.00790-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Metagenomic sequencing provides information on the metabolic capacities and taxonomic affiliations for members of a microbial community. When assessing metabolic functions in a community, missing genes in pathways can occur in two ways; the genes may legitimately be missing from the community whose DNA was sequenced, or the genes were missed during shotgun sequencing or failed to assemble, and thus the metabolic capacity of interest is wrongly absent from the sequence data. Here, we borrow and adapt occupancy modeling from macroecology to provide mathematical context to metabolic predictions from metagenomes. We review the five assumptions underlying occupancy modeling through the lens of microbial community sequence data. Using the methane cycle, we apply occupancy modeling to examine the presence and absence of methanogenesis and methanotrophy genes from nearly 10,000 metagenomes spanning global environments. We determine that methanogenesis and methanotrophy are positively correlated across environments, providing a predictive framework for assessing gene absences for these functions. We present this adaptation of macroecology’s occupancy modeling to metagenomics as a tool to quantify the uncertainty in predictions of the presence/absence of traits in environmental microbiological surveys. We further initiate a call for stronger metadata standards to accompany metagenome deposition, to enable robust statistical approaches in the future. IMPORTANCE Metagenomics is maturing rapidly as a field but is hampered by a lack of available statistical tools. A primary area of uncertainty is around missing genes or functions from a metagenomic data set. Here, we borrow an established modeling approach from macroecology and adapt it to metagenomic data sets. Rather than multiple sampling trips to a specific area to detect a species of interest (e.g., identifying a cardinal in a forest), we leverage the enormous amount of information within a metagenome and use multiple gene markers for a function of interest (e.g., subunits of an enzyme complex). We applied our adapted occupancy modeling to a case study examining methane cycling capacity. Our models show methanogens and methanotrophs are both more likely to cooccur than be present in the absence of the other guild. The lack of consistent and complete metadata is a significant hurdle for increasing the statistical rigor of metagenomic analyses.
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91
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Wang B, Stirling E, He Z, Ma B, Zhang H, Zheng X, Xiao F, Yan Q. Pollution alters methanogenic and methanotrophic communities and increases dissolved methane in small ponds. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 801:149723. [PMID: 34438138 DOI: 10.1016/j.scitotenv.2021.149723] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 08/07/2021] [Accepted: 08/12/2021] [Indexed: 05/28/2023]
Abstract
Small ponds have become a hotspot of greenhouse gas emissions, but our understanding of methane (CH4) cycling and its biological regulation in small polluted ponds remains limited. To assess how pollution affects CH4 content, we investigated dissolved CH4 concentrations, water and sediments properties, methanogenic and methanotrophic communities in two types of small polluted ponds. Compared with low pollution (LP) ponds, high pollution (HP) ponds showed significantly (P < 0.05) higher dissolved CH4 in water. Sequencing of methyl coenzyme M reductase (mcrA) and particulate methane monooxygenase (pmoA) genes showed that HP led to significant (P < 0.05) shifts of CH4-cycling microbial communities, with increased Shannon index of sediment methanogenic communities and water methanotrophic communities. There were also strong negative associations (P < 0.05) between dissolved CH4 concentrations and interdomain methanogen-methanotroph network connectivity in water and sediments, respectively. The partial least squares path modeling indicated that dissolved oxygen, total organic carbon, ammonium nitrogen and nitrate nitrogen of water, and total nitrogen and total carbon of sediment, and CH4-cycling microbes could regulate the CH4 content. This study clarified the effects of environmental deterioration on CH4 cycling in small ponds, highlighting the use of methanogen-methanotroph network connectivity to assess the CH4 production.
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Affiliation(s)
- Binhao Wang
- Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China; Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou 510006, China
| | - Erinne Stirling
- Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China; Acid Sulfate Soils Centre, School of Biological Sciences, The University of Adelaide, Adelaide 5005, Australia
| | - Zhili He
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou 510006, China; College of Agronomy, Hunan Agricultural University, Changsha 410128, China
| | - Bin Ma
- Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Zhejiang University, Hangzhou 310058, China; Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou 310058, China
| | - Hangjun Zhang
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
| | - Xiafei Zheng
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou 510006, China
| | - Fanshu Xiao
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou 510006, China
| | - Qingyun Yan
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou 510006, China.
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92
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Atmospheric Methane Consumption and Methanotroph Communities in West Siberian Boreal Upland Forest Ecosystems. FORESTS 2021. [DOI: 10.3390/f12121738] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Upland forest ecosystems are recognized as net sinks for atmospheric methane (CH4), one of the most impactful greenhouse gases. Biological methane uptake in these ecosystems occurs due to the activity of aerobic methanotrophic bacteria. Russia hosts one-fifth of the global forest area, with the most extensive forest landscapes located in West Siberia. Here, we report seasonal CH4 flux measurements conducted in 2018 in three types of stands in West Siberian middle taiga–Siberian pine, Aspen, and mixed forests. High rates of methane uptake of up to −0.184 mg CH4 m−2 h−1 were measured by a static chamber method, with an estimated total growing season consumption of 4.5 ± 0.5 kg CH4 ha−1. Forest type had little to no effect on methane fluxes within each season. Soil methane oxidation rate ranged from 0 to 8.1 ng CH4 gDW−1 h−1 and was negatively related to water-filled pore space. The microbial soil communities were dominated by the Alpha- and Gammaproteobacteria, Acidobacteriota and Actinobacteriota. The major group of 16S rRNA gene reads from methanotrophs belonged to uncultivated Beijerinckiaceae bacteria. Molecular identification of methanotrophs based on retrieval of the pmoA gene confirmed that Upland Soil Cluster Alpha was the major bacterial group responsible for CH4 oxidation.
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93
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Pelsma KAJ, In 't Zandt MH, Op den Camp HJM, Jetten MSM, Dean JF, Welte CU. Amsterdam urban canals contain novel niches for methane-cycling microorganisms. Environ Microbiol 2021; 24:82-97. [PMID: 34863018 PMCID: PMC9299808 DOI: 10.1111/1462-2920.15864] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 12/01/2021] [Accepted: 12/01/2021] [Indexed: 01/04/2023]
Abstract
Urbanised environments have been identified as hotspots of anthropogenic methane emissions. Especially urban aquatic ecosystems are increasingly recognised as important sources of methane. However, the microbiology behind these emissions remains unexplored. Here, we applied microcosm incubations and molecular analyses to investigate the methane‐cycling community of the Amsterdam canal system in the Netherlands. The sediment methanogenic communities were dominated by Methanoregulaceae and Methanosaetaceae, with co‐occurring methanotrophic Methanoperedenaceae and Methylomirabilaceae indicating the potential for anaerobic methane oxidation. Methane was readily produced after substrate amendment, suggesting an active but substrate‐limited methanogenic community. Bacterial 16S rRNA gene amplicon sequencing of the sediment revealed a high relative abundance of Thermodesulfovibrionia. Canal wall biofilms showed the highest initial methanotrophic potential under oxic conditions compared to the sediment. During prolonged incubations the maximum methanotrophic rate increased to 8.08 mmol gDW−1 d−1 that was concomitant with an enrichment of Methylomonadaceae bacteria. Metagenomic analysis of the canal wall biofilm lead to the recovery of a single methanotroph metagenome‐assembled genome. Taxonomic analysis showed that this methanotroph belongs to the genus Methyloglobulus. Our results underline the importance of previously unidentified and specialised environmental niches at the nexus of the natural and human‐impacted carbon cycle.
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Affiliation(s)
- Koen A J Pelsma
- Department of Microbiology, Radboud Institute for Biological and Environmental Sciences, Heyendaalseweg 135, Nijmegen, 6525 AJ, The Netherlands.,Netherlands Earth System Science Centre, Utrecht University, Heidelberglaan 2, Utrecht, 3584 CS, The Netherlands
| | - Michiel H In 't Zandt
- Department of Microbiology, Radboud Institute for Biological and Environmental Sciences, Heyendaalseweg 135, Nijmegen, 6525 AJ, The Netherlands.,Netherlands Earth System Science Centre, Utrecht University, Heidelberglaan 2, Utrecht, 3584 CS, The Netherlands
| | - Huub J M Op den Camp
- Department of Microbiology, Radboud Institute for Biological and Environmental Sciences, Heyendaalseweg 135, Nijmegen, 6525 AJ, The Netherlands
| | - Mike S M Jetten
- Department of Microbiology, Radboud Institute for Biological and Environmental Sciences, Heyendaalseweg 135, Nijmegen, 6525 AJ, The Netherlands.,Netherlands Earth System Science Centre, Utrecht University, Heidelberglaan 2, Utrecht, 3584 CS, The Netherlands.,Soehngen Institute of Anaerobic Microbiology, Radboud University, Heyendaalseweg 135, Nijmegen, 6525 AJ, The Netherlands
| | - Joshua F Dean
- School of Environmental Sciences, University of Liverpool, Liverpool, L69 3GP, UK
| | - Cornelia U Welte
- Department of Microbiology, Radboud Institute for Biological and Environmental Sciences, Heyendaalseweg 135, Nijmegen, 6525 AJ, The Netherlands.,Soehngen Institute of Anaerobic Microbiology, Radboud University, Heyendaalseweg 135, Nijmegen, 6525 AJ, The Netherlands
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94
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Seasonal dynamics of methanotrophic bacteria in a boreal oil sands end-pit lake. Appl Environ Microbiol 2021; 88:e0145521. [PMID: 34818104 DOI: 10.1128/aem.01455-21] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Base Mine Lake (BML) is the first full-scale demonstration end pit lake for the oil sands mining industry in Canada. We examined aerobic methanotrophic bacteria over all seasons for five years in this dimictic lake. Methanotrophs comprised up to 58% of all bacterial reads in 16S rRNA gene amplicon sequencing analyses (median 2.8%), and up to 2.7 × 104 cells mL-1 of water (median 0.5 × 103) based on qPCR of pmoA genes. Methanotrophic activity and populations in the lake water were highest during fall turnover, and remained high through the winter ice-covered period into spring turnover. They declined during summer stratification, especially in the epilimnion. Three methanotroph genera (Methylobacter, Methylovulum, and Methyloparacoccus) cycled seasonally, based on both relative and absolute abundance measurements. Methylobacter and Methylovulum populations peaked in winter/spring, when methane oxidation activity was psychrophilic. Methyloparacoccus populations increased in the water column through summer and fall, when methane oxidation was mesophilic, and also predominated in the underlying tailings sediment. Other, less abundant genera grew primarily during summer, possibly due to distinct CH4/O2 microniches created during thermal stratification. These data are consistent with temporal and spatial niche differentiation based on temperature, CH4 and O2. This pit lake displays methane cycling and methanotroph population dynamics similar to natural boreal lakes. Importance statement: The study examined methanotrophic bacteria in an industrial end pit lake, combining molecular DNA methods (both quantitative and descriptive) with biogeochemical measurements. The lake was sampled over 5 years, in all four seasons, as often as weekly, and included sub-ice samples. The resulting multi-season and multi-year dataset is unique in its size and intensity, and allowed us to document clear and consistent seasonal patterns of growth and decline of three methanotroph genera (Methylobacter, Methylovulum, and Methyloparacoccus). Laboratory experiments suggested that one major control of this succession was niche partitioning based on temperature. The study helps to understand microbial dynamics in engineered end-pit lakes, but we propose that the dynamics are typical of boreal stratified lakes, and widely applicable in microbial ecology and limnology. Methane oxidising bacteria are important model organisms in microbial ecology, and have implications for global climate change.
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95
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Multispecies populations of methanotrophic Methyloprofundus and cultivation of a likely dominant species from the Iheya North deep-sea hydrothermal field. Appl Environ Microbiol 2021; 88:e0075821. [PMID: 34788070 PMCID: PMC8788690 DOI: 10.1128/aem.00758-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Methyloprofundus clade is represented by uncultivated methanotrophic bacterial endosymbionts of deep-sea bathymodiolin mussels, but only a single free-living species has been cultivated to date. This study reveals the existence of free-living Methyloprofundus variants in the Iheya North deep-sea hydrothermal field in the mid-Okinawa Trough. A clade-targeted amplicon analysis of the particulate methane monooxygenase gene (pmoA) detected 647 amplicon sequence variants (ASVs) of the Methyloprofundus clade in microbial communities newly formed in in situ colonization systems. Such systems were deployed at colonies of bathymodiolin mussels and a galatheoid crab in diffuse-flow areas. These ASVs were classified into 161 species-like groups. The proportion of the species-like groups representing endosymbionts of mussels was unexpectedly low. A methanotrophic bacterium designated INp10, a likely dominant species in the Methyloprofundus population in this field, was enriched in a biofilm formed in a methane-fed cultivation system operated at 10°C. Genomic characterization with the gene transcription data set of INp10 from the biofilm suggested traits advantageous to niche competition in environments, such as mobility, chemotaxis, biofilm formation, offensive and defensive systems, and hypoxia tolerance. The notable metabolic traits that INp10 shares with some Methyloprofundus members are the use of lanthanide-dependent XoxF as the sole methanol dehydrogenase due to the absence of the canonical MxaFI, the glycolytic pathway using fructose-6-phosphate aldolase instead of fructose-1,6-bisphosphate aldolase, and the potential to perform partial denitrification from nitrate under oxygen-limited conditions. These findings help us better understand the ecological strategies of this possibly widespread marine-specific methanotrophic clade. IMPORTANCE The Iheya North deep-sea hydrothermal field in the mid-Okinawa Trough is characterized by abundant methane derived from organic-rich sediments and diverse chemosynthetic animal species, including those harboring methanotrophic bacterial symbionts, such as bathymodiolin mussels Bathymodiolus japonicus and “Bathymodiolus” platifrons and a galatheoid crab, Shinkaia crosnieri. Symbiotic methanotrophs have attracted significant attention, and yet free-living methanotrophs in this environment have not been studied in detail. We focused on the free-living Methyloprofundus spp. that thrive in this hydrothermal field and identified an unexpectedly large number of species-like groups in this clade. Moreover, we enriched and characterized a methanotroph whose genome sequence indicated that it corresponds to a new species in the genus Methyloprofundus. This species might be a dominant member of the indigenous Methyloprofundus population. New information on free-living Methyloprofundus populations suggests that the hydrothermal field is a promising locale at which to investigate the adaptive capacity and associated genetic diversity of Methyloprofundus spp.
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96
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Begmatov S, Savvichev AS, Kadnikov VV, Beletsky AV, Rusanov II, Klyuvitkin AA, Novichkova EA, Mardanov AV, Pimenov NV, Ravin NV. Microbial Communities Involved in Methane, Sulfur, and Nitrogen Cycling in the Sediments of the Barents Sea. Microorganisms 2021; 9:2362. [PMID: 34835487 PMCID: PMC8625253 DOI: 10.3390/microorganisms9112362] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Revised: 11/11/2021] [Accepted: 11/12/2021] [Indexed: 11/16/2022] Open
Abstract
A combination of physicochemical and radiotracer analysis, high-throughput sequencing of the 16S rRNA, and particulate methane monooxygenase subunit A (pmoA) genes was used to link a microbial community profile with methane, sulfur, and nitrogen cycling processes. The objects of study were surface sediments sampled at five stations in the northern part of the Barents Sea. The methane content in the upper layers (0-5 cm) ranged from 0.2 to 2.4 µM and increased with depth (16-19 cm) to 9.5 µM. The rate of methane oxidation in the oxic upper layers varied from 2 to 23 nmol CH4 L-1 day-1 and decreased to 0.3 nmol L-1 day-1 in the anoxic zone at a depth of 16-19 cm. Sulfate reduction rates were much higher, from 0.3 to 2.8 µmol L-1 day-1. In the surface sediments, ammonia-oxidizing Nitrosopumilaceae were abundant; the subsequent oxidation of nitrite to nitrate can be carried out by Nitrospira sp. Aerobic methane oxidation could be performed by uncultured deep-sea cluster 3 of gamma-proteobacterial methanotrophs. Undetectable low levels of methanogenesis were consistent with a near complete absence of methanogens. Anaerobic methane oxidation in the deeper sediments was likely performed by ANME-2a-2b and ANME-2c archaea in consortium with sulfate-reducing Desulfobacterota. Sulfide can be oxidized by nitrate-reducing Sulfurovum sp. Thus, the sulfur cycle was linked with the anaerobic oxidation of methane and the nitrogen cycle, which included the oxidation of ammonium to nitrate in the oxic zone and denitrification coupled to the oxidation of sulfide in the deeper sediments. Methane concentrations and rates of microbial biogeochemical processes in sediments in the northern part of the Barents Sea were noticeably higher than in oligotrophic areas of the Arctic Ocean, indicating that an increase in methane concentration significantly activates microbial processes.
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Affiliation(s)
- Shahjahon Begmatov
- Institute of Bioengineering, Research Center of Biotechnology of the Russian Academy of Sciences, 119071 Moscow, Russia; (S.B.); (V.V.K.); (A.V.B.); (A.V.M.)
| | - Alexander S. Savvichev
- Winogradsky Institute of Microbiology, Research Center of Biotechnology of the Russian Academy of Sciences, 119071 Moscow, Russia; (A.S.S.); (I.I.R.); (N.V.P.)
| | - Vitaly V. Kadnikov
- Institute of Bioengineering, Research Center of Biotechnology of the Russian Academy of Sciences, 119071 Moscow, Russia; (S.B.); (V.V.K.); (A.V.B.); (A.V.M.)
| | - Alexey V. Beletsky
- Institute of Bioengineering, Research Center of Biotechnology of the Russian Academy of Sciences, 119071 Moscow, Russia; (S.B.); (V.V.K.); (A.V.B.); (A.V.M.)
| | - Igor I. Rusanov
- Winogradsky Institute of Microbiology, Research Center of Biotechnology of the Russian Academy of Sciences, 119071 Moscow, Russia; (A.S.S.); (I.I.R.); (N.V.P.)
| | - Alexey A. Klyuvitkin
- Shirshov Institute of Oceanology of the Russian Academy of Sciences, 117997 Moscow, Russia; (A.A.K.); (E.A.N.)
| | - Ekaterina A. Novichkova
- Shirshov Institute of Oceanology of the Russian Academy of Sciences, 117997 Moscow, Russia; (A.A.K.); (E.A.N.)
| | - Andrey V. Mardanov
- Institute of Bioengineering, Research Center of Biotechnology of the Russian Academy of Sciences, 119071 Moscow, Russia; (S.B.); (V.V.K.); (A.V.B.); (A.V.M.)
| | - Nikolai V. Pimenov
- Winogradsky Institute of Microbiology, Research Center of Biotechnology of the Russian Academy of Sciences, 119071 Moscow, Russia; (A.S.S.); (I.I.R.); (N.V.P.)
- Il’ichev Pacific Institute of Oceanology, Far East Branch of the Russian Academy of Sciences, 690041 Vladivostok, Russia
| | - Nikolai V. Ravin
- Institute of Bioengineering, Research Center of Biotechnology of the Russian Academy of Sciences, 119071 Moscow, Russia; (S.B.); (V.V.K.); (A.V.B.); (A.V.M.)
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97
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Bussmann I, Horn F, Hoppert M, Klings KW, Saborowski A, Warnstedt J, Liebner S. Methylomonas albis sp. nov. and Methylomonas fluvii sp. nov.: Two cold-adapted methanotrophs from the river Elbe and emended description of the species Methylovulum psychrotolerans. Syst Appl Microbiol 2021; 44:126248. [PMID: 34624710 DOI: 10.1016/j.syapm.2021.126248] [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: 04/20/2021] [Revised: 08/16/2021] [Accepted: 08/29/2021] [Indexed: 10/20/2022]
Abstract
Three strains of methanotrophic bacteria (EbAT, EbBT and Eb1) were isolated from the River Elbe, Germany. These Gram-negative, rod-shaped or coccoid cells contain intracytoplasmic membranes perpendicular to the cell surface. Colonies and liquid cultures appeared bright-pink. The major cellular fatty acids were 12:0 and 14:0, in addition in Eb1 the FA 16:1ω5t was also dominant. Methane and methanol were utilized as sole carbon sources by EbBT and Eb1, while EbAT could not use methanol. All strains oxidize methane using the particulate methane monooxygenase. Both strains contain an additional soluble methane monooxygenase. The strains grew optimally at 15-25 °C and at pH 6 and 8. Based on 16S rRNA gene analysis recovered from the full genome, the phylogenetic position of EbAT is robustly outside any species clade with its closest relatives being Methylomonas sp. MK1 (98.24%) and Methylomonas sp. 11b (98.11%). Its closest type strain is Methylomonas methanica NCIMB11130 (97.91%). The 16S rRNA genes of EbBT are highly similar to Methylomonas methanica strains with Methylomonas methanica R-45371 as the closest relative (99.87% sequence identity). However, average nucleotide identity (ANI) and digital DNA-DNA-hybridization (dDDH) values reveal it as distinct species. The DNA G + C contents were 51.07 mol% and 51.5 mol% for EbAT and EbBT, and 50.7 mol% for Eb1, respectively. Strains EbAT and EbBT are representing two novel species within the genus Methylomonas. For strain EbAT we propose the name Methylomonas albis sp. nov (LMG 29958, JCM 32282) and for EbBT, we propose the name Methylomonas fluvii sp. nov (LMG 29959, JCM 32283). Eco-physiological descriptions for both strains are provided. Strain Eb1 (LMG 30323, JCM 32281) is a member of the species Methylovulum psychrotolerans. This genus is so far only represented by two isolates but Eb1 is the first isolate from a temperate environment; so, an emended description of the species is given.
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Affiliation(s)
- Ingeborg Bussmann
- Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Marine Station Helgoland, Kurpromenade 201, 27498 Helgoland, Germany
| | - Fabian Horn
- GFZ German Research Centre for Geosciences, Section Geomicrobiology, Telegrafenberg, 14473 Potsdam, Germany
| | - Michael Hoppert
- University of Göttingen, Institute of Microbiology and Genetics, Grisebachstr. 8, 37077 Göttingen, Germany
| | - Karl-Walter Klings
- Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Marine Station Helgoland, Kurpromenade 201, 27498 Helgoland, Germany
| | - Anke Saborowski
- GFZ German Research Centre for Geosciences, Section Geomicrobiology, Telegrafenberg, 14473 Potsdam, Germany
| | - Julia Warnstedt
- Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Marine Station Helgoland, Kurpromenade 201, 27498 Helgoland, Germany
| | - Susanne Liebner
- GFZ German Research Centre for Geosciences, Section Geomicrobiology, Telegrafenberg, 14473 Potsdam, Germany; University of Potsdam, Institute of Biochemistry and Biology, 14469 Potsdam, Germany
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98
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The Influence of Above-Ground Herbivory on the Response of Arctic Soil Methanotrophs to Increasing CH 4 Concentrations and Temperatures. Microorganisms 2021; 9:microorganisms9102080. [PMID: 34683401 PMCID: PMC8540837 DOI: 10.3390/microorganisms9102080] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 09/17/2021] [Accepted: 09/23/2021] [Indexed: 11/22/2022] Open
Abstract
Rising temperatures in the Arctic affect soil microorganisms, herbivores, and peatland vegetation, thus directly and indirectly influencing microbial CH4 production. It is not currently known how methanotrophs in Arctic peat respond to combined changes in temperature, CH4 concentration, and vegetation. We studied methanotroph responses to temperature and CH4 concentration in peat exposed to herbivory and protected by exclosures. The methanotroph activity was assessed by CH4 oxidation rate measurements using peat soil microcosms and a pure culture of Methylobacter tundripaludum SV96, qPCR, and sequencing of pmoA transcripts. Elevated CH4 concentrations led to higher CH4 oxidation rates both in grazed and exclosed peat soils, but the strongest response was observed in grazed peat soils. Furthermore, the relative transcriptional activities of different methanotroph community members were affected by the CH4 concentrations. While transcriptional responses to low CH4 concentrations were more prevalent in grazed peat soils, responses to high CH4 concentrations were more prevalent in exclosed peat soils. We observed no significant methanotroph responses to increasing temperatures. We conclude that methanotroph communities in these peat soils respond to changes in the CH4 concentration depending on their previous exposure to grazing. This “conditioning” influences which strains will thrive and, therefore, determines the function of the methanotroph community.
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99
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Burrows RM, van de Kamp J, Bodrossy L, Venarsky M, Coates-Marnane J, Rees G, Jumppanen P, Kennard MJ. Methanotroph community structure and processes in an inland river affected by natural gas macro-seeps. FEMS Microbiol Ecol 2021; 97:6367056. [PMID: 34498669 DOI: 10.1093/femsec/fiab130] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 09/07/2021] [Indexed: 11/13/2022] Open
Abstract
Methane availability in freshwaters is usually associated with spatial-temporal variation in methanogenesis. Unusually, however, natural gas macro-seeps occur along the Condamine River in eastern Australia which elevate ambient water-column methane concentrations more than 3,000 times. We quantified the spatial-temporal variation in methane oxidation rates and the total microbial and methanotroph community composition (through the amplification and sequencing of 16S rRNA and particulate methane monooxygenase (pmoA) genes), and the factors mediating this variation, in reaches with and without macro-seeps. Sediment methane oxidation rates were, on average, 29 times greater, and the abundance of methanotrophs significantly higher, in the vicinity of methane macro-seeps compared to non-seep sites. Methylocystis was the most abundant methanotroph group at all sites, but type Ib methanotrophs showed the steepest increase in abundance at seep sites. pmoA gene analysis identified these as clade 501, while 16S rRNA gene analysis identified these as the closely related genus Methylocaldum. Sediment methane oxidation rates and the relative abundance and composition of benthic microbial communities were primarily influenced by methane availability which was in turn related to variation in river discharge. Methane-derived carbon may be an important energy source for the aquatic food webs in reaches affected by natural gas macro-seeps.
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Affiliation(s)
- Ryan M Burrows
- School of Ecosystem and Forest Sciences, The University of Melbourne, Burnley Campus, Richmond, Victoria 3121, Australia.,Australian Rivers Institute, Griffith University, Nathan, Queensland 4111, Australia
| | - Jodie van de Kamp
- CSIRO Oceans and Atmosphere, Castray Esplanade, Hobart, Tasmania 7004, Australia
| | - Levente Bodrossy
- CSIRO Oceans and Atmosphere, Castray Esplanade, Hobart, Tasmania 7004, Australia
| | - Michael Venarsky
- Australian Rivers Institute, Griffith University, Nathan, Queensland 4111, Australia
| | - Jack Coates-Marnane
- Australian Rivers Institute, Griffith University, Nathan, Queensland 4111, Australia.,Healthy Land and Water, Ann Street, Brisbane, Queensland 4000, Australia
| | - Gavin Rees
- CSIRO Land and Water, and Institute of Land Water and Society, Charles Sturt University, Thurgoona, New South Wales, 2640, Australia
| | - Paavo Jumppanen
- CSIRO Oceans and Atmosphere, Castray Esplanade, Hobart, Tasmania 7004, Australia
| | - Mark J Kennard
- Australian Rivers Institute, Griffith University, Nathan, Queensland 4111, Australia
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100
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Rahalkar MC, Khatri K, Pandit P, Bahulikar RA, Mohite JA. Cultivation of Important Methanotrophs From Indian Rice Fields. Front Microbiol 2021; 12:669244. [PMID: 34539593 PMCID: PMC8447245 DOI: 10.3389/fmicb.2021.669244] [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: 02/18/2021] [Accepted: 08/09/2021] [Indexed: 11/15/2022] Open
Abstract
Methanotrophs are aerobic to micro-aerophilic bacteria, which oxidize and utilize methane, the second most important greenhouse gas. The community structure of the methanotrophs in rice fields worldwide has been studied mainly using culture-independent methods. Very few studies have focused on culturing methanotrophs from rice fields. We developed a unique method for the cultivation of methanotrophs from rice field samples. Here, we used a modified dilute nitrate mineral salts (dNMS) medium, with two cycles of dilution till extinction series cultivation with prolonged incubation time, and used agarose in the solid medium. The cultivation approach resulted in the isolation of methanotrophs from seven genera from the three major groups: Type Ia (Methylomonas, Methylomicrobium, and Methylocucumis), Type Ib (Methylocaldum and Methylomagnum), and Type II (Methylocystis and Methylosinus). Growth was obtained till 10–6–10–8 dilutions in the first dilution series, indicating the culturing of dominant methanotrophs. Our study was supported by 16S rRNA gene-based next-generation sequencing (NGS) of three of the rice samples. Our analyses and comparison with the global scenario suggested that the cultured members represented the major detected taxa. Strain RS1, representing a putative novel species of Methylomicrobium, was cultured; and the draft genome sequence was obtained. Genome analysis indicated that RS1 represented a new putative Methylomicrobium species. Methylomicrobium has been detected globally in rice fields as a dominant genus, although no Methylomicrobium strains have been isolated from rice fields worldwide. Ours is one of the first extensive studies on cultured methanotrophs from Indian rice fields focusing on the tropical region, and a unique method was developed. A total of 29 strains were obtained, which could be used as models for studying methane mitigation from rice fields and for environmental and biotechnological applications.
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Affiliation(s)
- Monali C Rahalkar
- C2, Bioenergy Group, MACS Agharkar Research Institute, Pune, India.,Department of Microbiology, Savitribai Phule Pune University, Pune, India
| | - Kumal Khatri
- C2, Bioenergy Group, MACS Agharkar Research Institute, Pune, India.,Department of Microbiology, Savitribai Phule Pune University, Pune, India
| | - Pranitha Pandit
- C2, Bioenergy Group, MACS Agharkar Research Institute, Pune, India.,Department of Microbiology, Savitribai Phule Pune University, Pune, India
| | - Rahul A Bahulikar
- Central Research Station, BAIF Development Research Foundation, Pune, India
| | - Jyoti A Mohite
- C2, Bioenergy Group, MACS Agharkar Research Institute, Pune, India.,Department of Microbiology, Savitribai Phule Pune University, Pune, India
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