scholarly journals Assessing the Effect of Humic Substances and Fe(III) as Potential Electron Acceptors for Anaerobic Methane Oxidation in a Marine Anoxic System

2020 ◽  
Vol 8 (9) ◽  
pp. 1288
Author(s):  
Sigrid van Grinsven ◽  
Jaap S. Sinninghe Damsté ◽  
Laura Villanueva
Keyword(s):  
Sulfate Reduction ◽  
Humic Substances ◽  
Methane Oxidation ◽  
Sea Water ◽  
Single Cells ◽  
Sodium Molybdate ◽  
Electron Acceptors ◽  
Anaerobic Methane Oxidation ◽  
Electron Shuttling ◽  
Incubation Experiments

Marine anaerobic methane oxidation (AOM) is generally assumed to be coupled to sulfate reduction, via a consortium of anaerobic methane-oxidizing archaea (ANME) and sulfate-reducing bacteria (SRB). ANME-1 are, however, often found as single cells, or only loosely aggregated with SRB, suggesting they perform a form of AOM independent of sulfate reduction. Oxidized metals and humic substances have been suggested as potential electron acceptors for ANME, but up to now, AOM linked to reduction of these compounds has only been shown for the ANME-2 and ANME-3 clades. Here, the effect of the electron acceptors anthraquinone-disulfonate (AQDS), a humic acids analog, and Fe3+ on anaerobic methane oxidation were assessed by incubation experiments with anoxic Black Sea water containing ANME-1b. Incubation experiments with 13C-methane and AQDS showed a stimulating effect of AQDS on methane oxidation. Fe3+ enhanced the ANME-1b abundance but did not substantially increase methane oxidation. Sodium molybdate, which was added as an inhibitor of sulfate reduction, surprisingly enhanced methane oxidation, possibly related to the dominant abundance of Sulfurospirillum in those incubations. The presented data suggest the potential involvement of ANME-1b in AQDS-enhanced anaerobic methane oxidation, possibly via electron shuttling to AQDS or via interaction with other members of the microbial community.

Electron shuttling mediated by humic substances fuels anaerobic methane oxidation and carbon burial in wetland sediments

2019 ◽  
Vol 650 ◽  
pp. 2674-2684 ◽  
Author(s):  
Edgardo I. Valenzuela ◽  
Karen A. Avendaño ◽  
Nagamani Balagurusamy ◽  
Sonia Arriaga ◽  
Cesar Nieto-Delgado ◽  
...  
Keyword(s):  
Humic Substances ◽  
Methane Oxidation ◽  
Anaerobic Methane Oxidation ◽  
Electron Shuttling ◽  
Carbon Burial

scholarly journals Contrasting Pathways for Anaerobic Methane Oxidation in Gulf of Mexico Cold Seep Sediments

mSystems ◽  
2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Adrien Vigneron ◽  
Eric B. Alsop ◽  
Perrine Cruaud ◽  
Gwenaelle Philibert ◽  
Benjamin King ◽  
...  
Keyword(s):  
Gene Expression ◽  
Electron Transfer ◽  
Gulf Of Mexico ◽  
Microbial Communities ◽  
Sulfate Reduction ◽  
Methane Oxidation ◽  
Sulfur Cycle ◽  
Anaerobic Methane Oxidation ◽  
Cold Seep ◽  
Biogenic Methane

ABSTRACTGulf of Mexico sediments harbor numerous hydrocarbon seeps associated with high sedimentation rates and thermal maturation of organic matter. These ecosystems host abundant and diverse microbial communities that directly or indirectly metabolize components of the emitted fluid. To investigate microbial function and activities in these ecosystems, metabolic potential (metagenomic) and gene expression (metatranscriptomic) analyses of two cold seep areas of the Gulf of Mexico were carried out. Seeps emitting biogenic methane harbored microbial communities dominated by archaeal anaerobic methane oxidizers of phylogenetic group 1 (ANME-1), whereas seeps producing fluids containing a complex mixture of thermogenic hydrocarbons were dominated by ANME-2 lineages. Metatranscriptome measurements in both communities indicated high levels of expression of genes for methane metabolism despite their distinct microbial communities and hydrocarbon composition. In contrast, the transcription level of sulfur cycle genes was quite different. In the thermogenic seep community, high levels of transcripts indicative of syntrophic anaerobic oxidation of methane (AOM) coupled to sulfate reduction were detected. This syntrophic partnership between the dominant ANME-2 and sulfate reducers potentially involves direct electron transfer through multiheme cytochromes. In the biogenic methane seep, genes from an ANME-1 lineage that are potentially involved in polysulfide reduction were highly expressed, suggesting a novel bacterium-independent anaerobic methane oxidation pathway coupled to polysulfide reduction. The observed divergence in AOM activities provides a new model for bacterium-independent AOM and emphasizes the variation that exists in AOM pathways between different ANME lineages.IMPORTANCECold seep sediments are complex and widespread marine ecosystems emitting large amounts of methane, a potent greenhouse gas, and other hydrocarbons. Within these sediments, microbial communities play crucial roles in production and degradation of hydrocarbons, modulating oil and gas emissions to seawater. Despite this ecological importance, our understanding of microbial functions and methane oxidation pathways in cold seep ecosystems is poor. Based on gene expression profiling of environmental seep sediment samples, the present work showed that (i) the composition of the emitted fluids shapes the microbial community in general and the anaerobic methanotroph community specifically and (ii) AOM by ANME-2 in this seep may be coupled to sulfate reduction byDeltaproteobacteriaby electron transfer through multiheme cytochromes, whereas AOM by ANME-1 lineages in this seep may involve a different, bacterium-independent pathway, coupling methane oxidation to elemental sulfur/polysulfide reduction.

Artificial electron acceptors decouple archaeal methane oxidation from sulfate reduction

Science ◽  
2016 ◽  
Vol 351 (6274) ◽  
pp. 703-707 ◽  
Author(s):  
S. Scheller ◽  
H. Yu ◽  
G. L. Chadwick ◽  
S. E. McGlynn ◽  
V. J. Orphan
Keyword(s):  
Sulfate Reduction ◽  
Methane Oxidation ◽  
Electron Acceptors

Anaerobic methane oxidation in metalliferous hydrothermal sediments: influence on carbon flux and decoupling from sulfate reduction

2012 ◽  
Vol 14 (10) ◽  
pp. 2726-2740 ◽  
Author(s):  
Scott D. Wankel ◽  
Melissa M. Adams ◽  
David T. Johnston ◽  
Colleen M. Hansel ◽  
Samantha B. Joye ◽  
...  
Keyword(s):  
Sulfate Reduction ◽  
Methane Oxidation ◽  
Carbon Flux ◽  
Anaerobic Methane Oxidation ◽  
Hydrothermal Sediments

Dynamic modeling of anaerobic methane oxidation coupled to sulfate reduction: role of elemental sulfur as intermediate

2021 ◽  
Vol 44 (4) ◽  
pp. 855-874
Author(s):  
Artin Hatzikioseyian ◽  
Susma Bhattarai ◽  
Chiara Cassarini ◽  
Giovanni Esposito ◽  
Piet N. L. Lens
Keyword(s):  
Sulfate Reduction ◽  
Methane Oxidation ◽  
Dynamic Modeling ◽  
Elemental Sulfur ◽  
Anaerobic Methane Oxidation

scholarly journals Using kinetic isotope effect to evaluate the significance of the sequential and parallel steps: formation of microbial consortium during reversible anaerobic methane oxidation coupled with sulfate reduction

2019 ◽  
Vol 79 (11) ◽  
pp. 2056-2067
Author(s):  
Vasily Vavilin ◽  
Lyudmila Lokshina ◽  
Sergey Rytov
Keyword(s):  
Experimental Data ◽  
Sulfate Reduction ◽  
Methane Oxidation ◽  
Isotope Fractionation ◽  
Sulfur Isotope ◽  
Biomass Accumulation ◽  
Anaerobic Methane Oxidation ◽  
Anaerobic Oxidation Of Methane ◽  
Oxidation Of Methane ◽  
Sulfur Isotope Fractionation

Abstract The purpose of this study was to describe the dynamics of anaerobic oxidation of methane (AOM) coupled with sulfate reduction (SR) using experimental data from a continuous incubation experiments published earlier in order to show that formation of consortia of anaerobic archaea (ANME) and Desulfosarcina-like bacteria (DSS) may have a significant effect on sulfur isotope fractionation. The dynamic simulation of reversible AOM by ANME coupled with SR by DSS was performed. This simulation took into account biomass growth and fractionation of stable isotopes of sulfur. Two kinetic schemes with and without ANME + DSS consortium formation were tested. The respective models were applied at five influent methane concentrations. A good fit to experimental data was obtained only when assuming active ANME and DSS biomass accumulation. The assumption about incorporation of reversibility of anaerobic methane oxidation and sulfate reduction did not improve the model's fit to experimental data. In accordance with both the models, sulfur isotope fractionation was smallest for the highest influent methane concentration. The model considering the formation of consortia of ANME + DSS is proved to be more appropriate.

scholarly journals Humic Substances Mediate Anaerobic Methane Oxidation Linked to Nitrous Oxide Reduction in Wetland Sediments

2020 ◽  
Vol 11 ◽  
Author(s):  
Edgardo I. Valenzuela ◽  
Claudia Padilla-Loma ◽  
Nicolás Gómez-Hernández ◽  
Nguyen E. López-Lozano ◽  
Sergio Casas-Flores ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Humic Substances ◽  
Methane Oxidation ◽  
Anaerobic Methane Oxidation ◽  
Oxide Reduction ◽  
Nitrous Oxide Reduction
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