The evolvement of anaerobic oxidation of methane in fresh water sediments

2020 ◽  
Author(s):  
Hanni Vigderovich ◽  
Werner Eckert ◽  
Orit Sivan
Keyword(s):  
Lake Sediments ◽  
Marine Sediments ◽  
Electron Acceptors ◽  
Lake Kinneret ◽  
Anaerobic Oxidation Of Methane ◽  
Anaerobic Oxidation ◽  
Ongoing Research ◽  
Oxidation Of Methane ◽  
Anoxic Environments

<p>Methane is a potent greenhouse gas that is produced naturally via microbial processes in anoxic environments (i.e. marine and lake sediments). The release of methane to the atmosphere from sediments is controlled by its aerobic and anaerobic oxidation. Anaerobic oxidation of methane (AOM) consumes up to 90% of the produced methane in marine sediments and over half of the produced methane in freshwater sediments. The most common electron acceptor in marine sediments for AOM is sulfate, however, in freshwater lake sediments, where sulfate concentrations are low, other electron acceptors can take its place (i.e. iron/manganese/nitrate). In lake Kinneret (Israel), iron-coupled AOM was evident by in-situ sedimentary profiles and in fresh sediment slurry incubations. Here we present geochemical and molecular analyses results of slurry experiments of long-term incubated lake Kinneret sediments with labeled <sup>13</sup>C-methane, different potential electron acceptors and a few inhibitors. These experiments are part of an ongoing research to characterize the AOM processes in lake sediments, and indicate another possible type of AOM that has evolved in the long-term incubated lake sediments.</p>

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 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.

scholarly journals Iron-Coupled Anaerobic Oxidation of Methane in Marine Sediments: A Review

2021 ◽  
Vol 9 (8) ◽  
pp. 875
Author(s):  
Hailin Yang ◽  
Shan Yu ◽  
Hailong Lu
Keyword(s):  
Iron Oxides ◽  
Marine Sediments ◽  
Electron Acceptor ◽  
Electron Acceptors ◽  
Anaerobic Oxidation Of Methane ◽  
Anaerobic Oxidation ◽  
Shallow Marine ◽  
Oxidation Of Methane ◽  
Shallow Marine Sediments ◽  
Forms Of Iron

Anaerobic oxidation of methane (AOM) is one of the major processes of oxidizing methane in marine sediments. Up to now, extensive studies about AOM coupled to sulfate reduction have been conducted because SO42− is the most abundant electron acceptor in seawater and shallow marine sediments. However, other terminal electron acceptors of AOM, such as NO3−, NO2−, Mn(IV), Fe(III), are more energetically favorable than SO42−. Iron oxides, part of the major components in deep marine sediments, might play a significant role as an electron acceptor in the AOM process, mainly below the sulfate–methane interface, mediated by physiologically related microorganisms. Iron-coupled AOM is possibly the dominant non-sulfate-dependent AOM process to consume methane in marine ecosystems. In this review, the conditions for iron-coupled AOM are summarized, and the forms of iron oxides as electron acceptors and the microbial mechanisms are discussed.

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

2019 ◽  
Vol 65 (4) ◽  
pp. 863-875 ◽  
Author(s):  
Guangyi Su ◽  
Jakob Zopfi ◽  
Haoyi Yao ◽  
Lea Steinle ◽  
Helge Niemann ◽  
...  
Keyword(s):  
Lake Sediments ◽  
Anaerobic Oxidation Of Methane ◽  
Anaerobic Oxidation ◽  
Oxidation Of Methane

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.

Anaerobic oxidation of methane (AOM) in marine sediments from the Skagerrak (Denmark): I. Geochemical and microbiological analyses

2008 ◽  
Vol 72 (12) ◽  
pp. 2868-2879 ◽  
Author(s):  
Nina J. Knab ◽  
Barry A. Cragg ◽  
Christian Borowski ◽  
R. John Parkes ◽  
Richard Pancost ◽  
...  
Keyword(s):  
Marine Sediments ◽  
Anaerobic Oxidation Of Methane ◽  
Anaerobic Oxidation ◽  
Oxidation Of Methane ◽  
Microbiological Analyses

scholarly journals Anaerobic oxidation of methane alters sediment records of sulfur, iron and phosphorus in the Black Sea

2016 ◽  
Author(s):  
Matthias Egger ◽  
Peter Kraal ◽  
Tom Jilbert ◽  
Fatimah Sulu-Gambari ◽  
Célia J. Sapart ◽  
...  
Keyword(s):  
Lake Sediments ◽  
Pore Water ◽  
Black Sea ◽  
The Black Sea ◽  
Anaerobic Oxidation Of Methane ◽  
Anaerobic Oxidation ◽  
Fe Oxide ◽  
Fe Oxides ◽  
Oxidation Of Methane ◽  
High Concentrations

Abstract. The surface sediments in the Black Sea are underlain by extensive deposits of iron (Fe) oxide-rich lake sediments that were deposited prior to the inflow of marine Mediterranean Sea waters ca. 9000 years ago. The subsequent downward diffusion of marine sulfate into the methane-bearing lake sediments has led to a multitude of diagenetic reactions in the sulfate-methane transition zone (SMTZ), including anaerobic oxidation of methane (AOM) with sulfate. While the sedimentary cycles of sulfur (S), methane and Fe in the SMTZ have been extensively studied, relatively little is known about the diagenetic alterations of the sediment record occurring below the SMTZ. Here we combine detailed geochemical analyses of the sediment and pore water with multicomponent diagenetic modeling to study the diagenetic alterations below the SMTZ at two sites in the western Black Sea. We focus on the dynamics of Fe, S and phosphorus (P) and demonstrate that diagenesis has strongly overprinted the sedimentary burial records of these elements. Our results show that sulfate-mediated AOM substantially enhances the downward diffusive flux of sulfide into the deep limnic deposits. During this downward sulfidization, Fe oxides, Fe carbonates and Fe phosphates (e.g. vivianite) are converted to sulfide phases, leading to an enrichment in solid phase S and the release of phosphate to the pore water. Below the sulfidization front, high concentrations of dissolved ferrous Fe (Fe2+) lead to sequestration of downward diffusing phosphate as authigenic vivianite, resulting in a transient accumulation of total P directly below the sulfidization front. Our model results further demonstrate that downward migrating sulfide becomes partly re-oxidized to sulfate due to reactions with oxidized Fe minerals, fueling a cryptic S cycle and thus stimulating slow rates of sulfate-driven AOM (~ 1–100 pmol cm−3 d−1) in the sulfate-depleted limnic deposits. However, this process is unlikely to explain the observed release of dissolved Fe2+ below the SMTZ. Instead, we suggest that besides organoclastic Fe oxide reduction, AOM coupled to the reduction of Fe oxides may also provide a possible mechanism for the high concentrations of Fe2+ in the pore water at depth. Our results reveal that methane plays a key role in the diagenetic alterations of Fe, S and P records in Black Sea sediments. The downward sulfidization into the limnic deposits is enhanced through sulfate-driven AOM with sulfate and AOM with Fe oxides may provide a deep source of dissolved Fe2+ that drives the sequestration of P in vivianite below the sulfidization front.

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