scholarly journals Anaerobic oxidation of methane in hypersaline cold seep sediments

2012 ◽  
Vol 83 (1) ◽  
pp. 214-231 ◽  
Author(s):  
Loïs Maignien ◽  
R. John Parkes ◽  
Barry Cragg ◽  
Helge Niemann ◽  
Katrin Knittel ◽  
...  
Keyword(s):  
Cold Seep ◽  
Anaerobic Oxidation Of Methane ◽  
Anaerobic Oxidation ◽  
Oxidation Of Methane

scholarly journals Phosphorus Species in Deep-Sea Carbonate Deposits: Implications for Phosphorus Cycling in Cold Seep Environments

Minerals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 645
Author(s):  
Junlie Zhou ◽  
Mengran Du ◽  
Jiwei Li ◽  
Hengchao Xu ◽  
Kaiwen Ta ◽  
...  
Keyword(s):  
Deep Sea ◽  
Cold Seep ◽  
Anaerobic Oxidation Of Methane ◽  
Cold Seeps ◽  
Organic P ◽  
Anaerobic Oxidation ◽  
Phosphorus Species ◽  
China Sea ◽  
Oxidation Of Methane ◽  
Deep Sediments

Phosphorus (P) is an important nutrient for biological communities in cold seeps. However, our knowledge on the source, species, and cycling of P in cold seep environments is limited. In this study, the concentration, species, and micro to nanometer scale distribution of P in seep carbonates were examined at three deep-sea cold seeps in the South China Sea and East China Sea. The Ca-P accounts for the largest proportion of P—followed by detrital-P, Fe-P, organic-P, and exchangeable-P. The distribution patterns of Ca-P, detrital-P, and organic-P in the seep carbonates differ from one another, as shown by elemental mapping with NanoSIMS and scanning electron microscopy. The covariation of P with Ca and C reveals that Ca-P co-precipitates with Ca-carbonate, which is linked to the process of sulfate-driven anaerobic oxidation of methane. Organic-P is also observed within biofilm-like organic carbon aggregates, revealing the microbial enrichment of P by fluids in the process of anaerobic oxidation of methane. P with a granulated morphology was identified as detrital-P derived from deep sediments. Most importantly, it is evident that Ca-P is positively correlated to the Fe content in all the seep carbonates. This indicates the likelihood that the dissolved P in cold-seep fluids is released primarily from Fe oxides through Fe-driven anaerobic oxidation of methane in deep sediments. These processes associated with different species of P may have significant implications for P geochemical cycling and anaerobic oxidation of methane impelled by Fe and sulfate reduction in cold seep environments.

scholarly journals An experimental study on short-term changes in the anaerobic oxidation of methane in response to varying methane and sulfate fluxes

2009 ◽  
Vol 6 (5) ◽  
pp. 867-876 ◽  
Author(s):  
G. Wegener ◽  
A. Boetius
Keyword(s):  
Cold Seep ◽  
Anaerobic Oxidation Of Methane ◽  
Cold Seeps ◽  
Anaerobic Oxidation ◽  
Short Term ◽  
Sulfate Reducing ◽  
Oxidation Of Methane ◽  
Column System ◽  
Methane Fluxes ◽  
Anaerobic Methanotrophs

Abstract. A major role in regulation of global methane fluxes has been attributed to the process of anaerobic oxidation of methane (AOM), which is performed by consortia of methanotrophic archaea and sulfate reducing bacteria. An important question remains how these energy limited, slow growing microorganisms with generation times of 3–7 months respond to rapid natural variations in methane fluxes at cold seeps. We used an experimental flow-through column system filled with cold seep sediments naturally enriched in methanotrophic communities, to test their responses to short-term variations in methane and sulfate fluxes. At stable methane and sulfate concentrations of ~2 mM and 28 mM, respectively, we measured constant rates of AOM and sulfate reduction (SR) for up to 160 days of incubation. When percolated with methane-free medium, the anaerobic methanotrophs ceased to produce sulfide. After a starvation phase of 40 days, the addition of methane restored former AOM and SR rates immediately. At methane concentrations between 0–2.3 mM we measured a linear correlation between methane availability, AOM and SR. At constant fluid flow velocities of 30 m yr−1, ca. 50% of the methane was consumed by the anaerobic methanotrophic (ANME) population at all concentrations tested. Reducing the sulfate concentration from 28 to 1 mM, a decrease in AOM and SR by 50% was observed, and 45% of the methane was consumed. Hence, the marine anaerobic methanotrophs (ANME) are capable of oxidizing substantial amounts of methane over a wide and variable range of fluxes of the reaction educts.

scholarly journals Miniaturized biosignature analysis reveals implications for the formation of cold seep carbonates at Hydrate Ridge (off Oregon, USA)

2008 ◽  
Vol 5 (3) ◽  
pp. 731-738 ◽  
Author(s):  
T. Leefmann ◽  
J. Bauermeister ◽  
A. Kronz ◽  
V. Liebetrau ◽  
J. Reitner ◽  
...  
Keyword(s):  
Cold Seep ◽  
Chemical Compositions ◽  
Anaerobic Oxidation Of Methane ◽  
Anaerobic Oxidation ◽  
Sulfate Reducing ◽  
Oxidation Of Methane ◽  
Hydrate Ridge ◽  
Inorganic Matter ◽  
The Individual ◽  
A Minor

Abstract. Methane-related carbonates from Hydrate Ridge typically show several macroscopically distinguishable mineral phases, namely whitish aragonite, lucent aragonite, and gray micrite. The relationship of these phases to particular microorganisms or biogeochemical processes is as yet unclear. We used a miniaturized biomarker technique on mg samples, combined with factor analysis and subsequent electron microprobe analysis, to study lipid biomarkers and chemical compositions of the individual phases. This allows us to identify particular mechanisms involved in the formation of the different carbonate precipitates. Our combined analysis of biomarkers and petrographic traits shows that most of the lipids related to the anaerobic oxidation of methane (>90% by weight) are concentrated within only a minor compartment (~20% by volume) of the Hydrate Ridge carbonates, the whitish aragonite. The patterns indicate that the whitish aragonite represents fossilized biofilms of methanotrophic consortia containing mainly archaea of the ANME-2 group and sulfate reducing bacteria, whereas the precipitation of the lucent aragonite may have lacked the immediate proximity of microorganisms during formation. By contrast, the gray micrite formed by incorporation of allochthonous organic and inorganic matter during carbonate precipitation induced by the anaerobic oxidation of methane involving ANME-1 archaea.

scholarly journals Physiology and Distribution of Archaeal Methanotrophs That Couple Anaerobic Oxidation of Methane with Sulfate Reduction

2019 ◽  
Vol 83 (3) ◽  
Author(s):  
S. Bhattarai ◽  
C. Cassarini ◽  
P. N. L. Lens
Keyword(s):  
Hydrothermal Vents ◽  
Cold Seep ◽  
Anaerobic Oxidation Of Methane ◽  
Anaerobic Oxidation ◽  
Oxidation Of Methane ◽  
Marine Habitats ◽  
Anaerobic Methanotrophs ◽  
Enriched Cultures ◽  
Global Carbon ◽  
Thermogenic Methane

SUMMARY In marine anaerobic environments, methane is oxidized where sulfate-rich seawater meets biogenic or thermogenic methane. In those niches, a few phylogenetically distinct microbial types, i.e., anaerobic methanotrophs (ANME), are able to grow through anaerobic oxidation of methane (AOM). Due to the relevance of methane in the global carbon cycle, ANME have drawn the attention of a broad scientific community for 4 decades. This review presents and discusses the microbiology and physiology of ANME up to the recent discoveries, revealing novel physiological types of anaerobic methane oxidizers which challenge the view of obligate syntrophy for AOM. An overview of the drivers shaping the distribution of ANME in different marine habitats, from cold seep sediments to hydrothermal vents, is given. Multivariate analyses of the abundance of ANME in various habitats identify a distribution of distinct ANME types driven by the mode of methane transport. Intriguingly, ANME have not yet been cultivated in pure culture, despite intense attempts. Further advances in understanding this microbial process are hampered by insufficient amounts of enriched cultures. This review discusses the advantages, limitations, and potential improvements for ANME laboratory-based cultivation systems.

scholarly journals Short-term changes in anaerobic oxidation of methane in response to varying methane and sulfate fluxes

2008 ◽  
Vol 5 (4) ◽  
pp. 3069-3090 ◽  
Author(s):  
G. Wegener ◽  
A. Boetius
Keyword(s):  
Cold Seep ◽  
Anaerobic Oxidation Of Methane ◽  
Cold Seeps ◽  
Anaerobic Oxidation ◽  
Short Term ◽  
Oxidation Of Methane ◽  
Column System ◽  
Wide Range ◽  
Methane Fluxes ◽  
Anaerobic Methanotrophs

Abstract. A major role in global methane fluxes has been attributed to the process of anaerobic oxidation of methane, which is performed by consortia of methanotrophic archaea and sulfate reducing bacteria. An important question remains how these very slow growing microorganisms with generation times of 3–7 months respond to natural variations in methane fluxes at cold seeps. Here, we used an experimental flow-through column system filled with cold seep sediments naturally enriched in methanotrophic communities, to test their response to short-term variations in methane and sulfate fluxes. At stable methane and sulfate concentrations of ~2 mM and 28 mM, respectively, we measured constant rates of anaerobic oxidation of methane (AOM) and sulfide production (SR) for up to 160 days of incubation. When percolated with methane-free medium, the anaerobic methanotrophs ceased to oxidize methane and to produce sulfide. After a starvation phase of 40 days, the addition of methane restored former AOM and SR rates immediately. At methane concentrations between 0–2.3 mM we measured a linear correlation between methane availability, AOM and SR. At constant fluid flow rates of 30 m yr−1, ca. 50% of the methane was consumed by the ANME population at all concentrations tested. Reducing the sulfate concentration from 28 to 1 mM, a decrease in AOM and SR by 35% was observed. Hence, the marine anaerobic methanotrophs (ANME) are capable to consume substantial amounts of methane rising from the subsurface seabed to the hydrosphere over a wide range of fluxes of methane and sulfate.

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