scholarly journals Anaerobic Oxidation of Methane in Sediments of Lake Constance, an Oligotrophic Freshwater Lake

2011 ◽  
Vol 77 (13) ◽  
pp. 4429-4436 ◽  
Author(s):  
Jörg S. Deutzmann ◽  
Bernhard Schink
Keyword(s):  
Methane Oxidation ◽  
Electron Acceptors ◽  
Molecular Techniques ◽  
Freshwater Lake ◽  
Lake Constance ◽  
Anaerobic Oxidation Of Methane ◽  
Anaerobic Oxidation ◽  
Terminal Electron Acceptor ◽  
Oxidation Of Methane ◽  
Freshwater Habitats

ABSTRACTAnaerobic oxidation of methane (AOM) with sulfate as terminal electron acceptor has been reported for various environments, including freshwater habitats, and also, nitrate and nitrite were recently shown to act as electron acceptors for methane oxidation in eutrophic freshwater habitats. Radiotracer experiments with sediment material of Lake Constance, an oligotrophic freshwater lake, were performed to follow14CO2formation from14CH4in sediment incubations in the presence of different electron acceptors, namely, nitrate, nitrite, sulfate, or oxygen. Whereas14CO2formation without and with sulfate addition was negligible, addition of nitrate increased14CO2formation significantly, suggesting that AOM could be coupled to denitrification. Nonetheless, denitrification-dependent AOM rates remained at least 1 order of magnitude lower than rates of aerobic methane oxidation. Using molecular techniques, putative denitrifying methanotrophs belonging to the NC10 phylum were detected on the basis of thepmoAand 16S rRNA gene sequences. These findings show that sulfate-dependent AOM was insignificant in Lake constant sediments. However, AOM can also be coupled to denitrification in this oligotrophic freshwater habitat, providing first indications that this might be a widespread process that plays an important role in mitigating methane emissions.

scholarly journals Manganese/iron-supported sulfate-dependent anaerobic oxidation of methane by archaea in lake sediments

2019 ◽  
Author(s):  
Guangyi Su ◽  
Jakob Zopfi ◽  
Haoyi Yao ◽  
Lea Steinle ◽  
Helge Niemann ◽  
...  
Keyword(s):  
Lake Sediments ◽  
16S Rrna Gene Sequencing ◽  
Electron Acceptors ◽  
Rrna Gene ◽  
Anaerobic Oxidation Of Methane ◽  
Anaerobic Oxidation ◽  
Sequencing Data ◽  
Oxidation Of Methane ◽  
Freshwater Habitats ◽  
Rrna Gene Sequencing

AbstractAnaerobic oxidation of methane (AOM) by methanotrophic archaea is an important sink of this greenhouse gas in marine sediments. However, evidence for AOM in freshwater habitats is rare, and little is known about the pathways, electron acceptors and microbes involved. Here, we show that AOM occurs in anoxic sediments of a lake in southern Switzerland (Lake Cadagno). Combined AOM-rate and 16S rRNA gene-sequencing data suggest thatCandidatusMethanoperedens archaea are responsible for the observed methane oxidation. Members of the Methanoperedenaceae family were previously reported to conduct nitrate- or iron/manganese-dependent AOM. However, we demonstrate for the first time that the methanotrophic archaea do not necessarily rely upon these oxidants as terminal electron acceptors directly, but mainly perform canonical sulfate-dependent AOM, which under sulfate-starved conditions can be supported by metal (Mn, Fe) oxides through oxidation of reduced sulfur species to sulfate. The correspondence of high abundances of Desulfobulbaceae andCandidatusMethanoperedens at the same sediment depth confirm the interdependence of anaerobic methane-oxidizing archaea and sulfate-reducing bacteria. The relatively high abundance and widespread distribution ofCandidatusMethanoperedens in lake sediments highlight their potentially important role in mitigating methane emissions from terrestrial freshwater environments to the atmosphere, analogous to ANME-1, -2 and -3 in marine settings.

scholarly journals Anaerobic oxidation of methane in grassland soils used for cattle husbandry

2012 ◽  
Vol 9 (10) ◽  
pp. 3891-3899 ◽  
Author(s):  
A. Bannert ◽  
C. Bogen ◽  
J. Esperschütz ◽  
A. Koubová ◽  
F. Buegger ◽  
...  
Keyword(s):  
Methane Oxidation ◽  
Enrichment Culture ◽  
Anaerobic Oxidation Of Methane ◽  
Anaerobic Oxidation ◽  
Incubation Experiment ◽  
Nutrient Source ◽  
Oxidation Activity ◽  
Oxidation Of Methane ◽  
Cattle Husbandry

Abstract. While the importance of anaerobic methane oxidation has been reported for marine ecosystems, the role of this process in soils is still questionable. Grasslands used as pastures for cattle overwintering show an increase in anaerobic soil micro-sites caused by animal treading and excrement deposition. Therefore, anaerobic potential methane oxidation activity of severely impacted soil from a cattle winter pasture was investigated in an incubation experiment under anaerobic conditions using 13C-labelled methane. We were able to detect a high microbial activity utilizing CH4 as nutrient source shown by the respiration of 13CO2. Measurements of possible terminal electron acceptors for anaerobic oxidation of methane were carried out. Soil sulfate concentrations were too low to explain the oxidation of the amount of methane added, but enough nitrate and iron(III) were detected. However, only nitrate was consumed during the experiment. 13C-PLFA analyses clearly showed the utilization of CH4 as nutrient source mainly by organisms harbouring 16:1ω7 PLFAs. These lipids were also found as most 13C-enriched fatty acids by Raghoebarsing et al. (2006) after addition of 13CH4 to an enrichment culture coupling denitrification of nitrate to anaerobic oxidation of methane. This might be an indication for anaerobic oxidation of methane by relatives of "Candidatus Methylomirabilis oxyfera" in the investigated grassland soil under the conditions of the incubation experiment.

scholarly journals Anaerobic oxidation of methane in an iron-rich Danish freshwater lake sediment

2013 ◽  
Vol 58 (2) ◽  
pp. 546-554 ◽  
Author(s):  
Katrin à. Norði ◽  
Bo Thamdrup ◽  
Carsten J. Schubert
Keyword(s):  
Lake Sediment ◽  
Freshwater Lake ◽  
Anaerobic Oxidation Of Methane ◽  
Anaerobic Oxidation ◽  
Oxidation Of Methane

scholarly journals Anaerobic oxidation of methane in grassland soils used for cattle husbandry

2012 ◽  
Vol 9 (4) ◽  
pp. 4919-4945
Author(s):  
A. Bannert ◽  
C. Bogen ◽  
J. Esperschütz ◽  
A. Koubová ◽  
F. Buegger ◽  
...  
Keyword(s):  
Methane Oxidation ◽  
Anaerobic Methane Oxidation ◽  
Anaerobic Oxidation Of Methane ◽  
Type I ◽  
Anaerobic Oxidation ◽  
Nutrient Source ◽  
Oxidation Activity ◽  
Oxidation Of Methane ◽  
Cattle Husbandry

Abstract. While the importance of anaerobic methane oxidation has been reported for marine ecosystems, the role of this process in soils is still questionable. Grasslands used as pastures for cattle-overwintering show an increase in anaerobic soil micro-sites caused by animal treading and excrement deposition. Therefore anaerobic potential methane oxidation activity of severely impacted soil from a cattle winter pasture was investigated in an incubation experiment under anaerobic conditions using 13C-labeled methane. We were able to detect a high microbial activity utilizing CH4 as nutrient source shown by the respiration of 13CO2. Measurements of possible terminal electron acceptors for anaerobic oxidation of methane were carried out. Soil sulfate concentrations were too low to explain the oxidation of the amount of methane added, but enough nitrate and iron(III) were detected. However, only nitrate was consumed during the experiment. 13C-PLFA analyses clearly showed the utilization of CH4 as nutrient source mainly by organisms harbouring 16:1ω7 PLFAs. These lipids were found in Gram-negative microorganisms and anaerobes. The fact that these lipids are also typical for type I methanotrophs, known as aerobic methane oxidizers, might indicate a link between aerobic and anaerobic methane oxidation.

scholarly journals Modification of methane oxidation pathways during long-term incubations of methanic lake sediments

2021 ◽  
Author(s):  
Hanni Vigderovich ◽  
Werner Eckert ◽  
Michal Elul ◽  
Maxim Rubin-Blum ◽  
Marcus Elvert ◽  
...  
Keyword(s):  
Lake Sediments ◽  
Carbon Isotope ◽  
Iron Oxides ◽  
Methane Oxidation ◽  
Electron Acceptors ◽  
Anaerobic Oxidation Of Methane ◽  
Methanotrophic Bacteria ◽  
Oxidation Of Methane ◽  
Isotope Measurements

Abstract. Anaerobic oxidation of methane (AOM) is one of the major processes limiting the release of the greenhouse gas methane from natural environments. In Lake Kinneret sediments, iron-coupled AOM (Fe-AOM) was suggested to play a substantial role (10–15 % relative to methanogenesis) in the methanic zone (> 20 cm sediment depth), based on geochemical profiles and experiments on fresh sediments. Apparently, the oxidation of methane is mediated by a combination of mcr gene bearing archaea and aerobic bacterial methanotrophs. Here we aimed to investigate the survival of this complex microbial interplay under controlled conditions. We followed the AOM process during long-term (~18 months) anaerobic slurry experiments of these methanic sediments with two stages of incubations and additions of 13C-labeled methane, multiple electron acceptors and inhibitors. After these incubation stages carbon isotope measurements in the dissolved inorganic pool still showed considerable AOM (3–8 % relative to methanogenesis). Specific lipid carbon isotope measurements and metagenomic analyses indicate that after the prolonged incubation aerobic methanotrophic bacteria were no longer involved in the oxidation process, whereas mcr gene bearing archaea were most likely responsible for oxidizing the methane. Humic substances and iron oxides are likely electron acceptors to support this oxidation, whereas sulfate, manganese, nitrate, and nitrite did not support the AOM in these methanic sediments. Our results suggest in the natural lake sediments methanotrophic bacteria are responsible for part of the methane oxidation by the reduction of combined micro levels of oxygen and iron oxides in a cryptic cycle, while the rest of the methane is converted by reverse methanogenesis. After long-term incubation, the latter prevails without bacterial methanotropic activity and with a different iron reduction pathway.

Humic substances as electron acceptors for anaerobic oxidation of methane driven by ANME-2d

2019 ◽  
Vol 164 ◽  
pp. 114935 ◽  
Author(s):  
Ya-Nan Bai ◽  
Xiu-Ning Wang ◽  
Jun Wu ◽  
Yong-Ze Lu ◽  
Liang Fu ◽  
...  
Keyword(s):  
Humic Substances ◽  
Electron Acceptors ◽  
Anaerobic Oxidation Of Methane ◽  
Anaerobic Oxidation ◽  
Oxidation Of Methane

scholarly journals Anaerobic Oxidation of Methane Coupled to Nitrite Reduction by Halophilic Marine NC10 Bacteria

2015 ◽  
Vol 81 (16) ◽  
pp. 5538-5545 ◽  
Author(s):  
Zhanfei He ◽  
Sha Geng ◽  
Chaoyang Cai ◽  
Shuai Liu ◽  
Yan Liu ◽  
...  
Keyword(s):  
16S Rrna ◽  
Methane Oxidation ◽  
Nitrite Reduction ◽  
Substrate Affinity ◽  
Rrna Gene ◽  
Anaerobic Oxidation Of Methane ◽  
Anaerobic Oxidation ◽  
Oxidation Activity ◽  
Optimal Salinity ◽  
Oxidation Of Methane

ABSTRACTAnaerobic oxidation of methane (AOM) coupled to nitrite reduction is a novel AOM process that is mediated by denitrifying methanotrophs. To date, enrichments of these denitrifying methanotrophs have been confined to freshwater systems; however, the recent findings of 16S rRNA andpmoAgene sequences in marine sediments suggest a possible occurrence of AOM coupled to nitrite reduction in marine systems. In this research, a marine denitrifying methanotrophic culture was obtained after 20 months of enrichment. Activity testing and quantitative PCR (qPCR) analysis were then conducted and showed that the methane oxidation activity and the number of NC10 bacteria increased correlatively during the enrichment period. 16S rRNA gene sequencing indicated that only bacteria in group A of the NC10 phylum were enriched and responsible for the resulting methane oxidation activity, although a diverse community of NC10 bacteria was harbored in the inoculum. Fluorescencein situhybridization showed that NC10 bacteria were dominant in the enrichment culture after 20 months. The effect of salinity on the marine denitrifying methanotrophic culture was investigated, and the apparent optimal salinity was 20.5‰, which suggested that halophilic bacterial AOM coupled to nitrite reduction was obtained. Moreover, the apparent substrate affinity coefficients of the halophilic denitrifying methanotrophs were determined to be 9.8 ± 2.2 μM for methane and 8.7 ± 1.5 μM for nitrite.

scholarly journals Different impacts of an electron shuttle on nitrate- and nitrite-dependent anaerobic oxidation of methane in paddy soil

2021 ◽  
Vol 67 (No. 5) ◽  
pp. 264-269
Author(s):  
Yaohong Zhang ◽  
Fangyuan Wang
Keyword(s):  
Organic Matter ◽  
Paddy Soil ◽  
Anaerobic Oxidation Of Methane ◽  
Electron Shuttle ◽  
Anaerobic Oxidation ◽  
Terminal Electron Acceptor ◽  
Electron Shuttles ◽  
Oxidation Of Methane ◽  
Nitrate And Nitrite ◽  
C Assimilation

Quinones, redox-active functional groups in soil organic matter, can act as electron shuttles for microbial anaerobic transformation. Here, we used <sup>13</sup>CH<sub>4</sub> to trace <sup>13</sup>C conversion (<sup>13</sup>C-CO<sub>2</sub> + <sup>13</sup>C-SOC) to investigate the influence of an artificial electron shuttle (anthraquinone-2,6-disulfonate, AQDS) on denitrifying anaerobic methane oxidation (DAMO) in paddy soil. The results showed that AQDS could act as the terminal electron acceptor for the anaerobic oxidation of methane (AOM) in the paddy field. Moreover, AQDS significantly enhanced nitrate-dependent AOM rates and the amount of <sup>13</sup>C-CH<sub>4</sub> assimilation to soil organic carbon (SOC), whereas it was remarkably reduced nitrite-dependent AOM rates and <sup>13</sup>C assimilation. Ultimately, AQDS notably increased the total DAMO rates and <sup>13</sup>C assimilation to SOC. However, the electron shuttle did not change the percentage of <sup>13</sup>C-SOC in total <sup>13</sup>C-CH<sub>4</sub> conversion. These results suggest that electron shuttles in the natural organic matter might be able to offset methane emission by facilitating AOM coupled with the denitrification process.

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