Methane emission from hypersaline microbial mats: Lack of aerobic methane oxidation activity

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.

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Density-dependent enhancement of methane oxidation activity and growth of Methylocystis sp. by a non-methanotrophic bacterium Sphingopyxis sp

Biotechnology Reports ◽

10.1016/j.btre.2014.09.007 ◽

2014 ◽

Vol 4 ◽

pp. 128-133 ◽

Cited By ~ 8

Author(s):

So-Yeon Jeong ◽

Kyung-Suk Cho ◽

Tae Gwan Kim

Keyword(s):

Methane Oxidation ◽

Oxidation Activity ◽

Methanotrophic Bacterium ◽

Density Dependent

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On the methane oxidation activity of Sr2(MgMo)2O6-δ: a potential anode material for direct hydrocarbon solid oxide fuel cells

Journal of Materials Chemistry ◽

10.1039/c1jm10523j ◽

2011 ◽

Vol 21 (20) ◽

pp. 7443 ◽

Cited By ~ 15

Author(s):

Michael van den Bossche ◽

Steven McIntosh

Keyword(s):

Fuel Cells ◽

Solid Oxide Fuel Cells ◽

Anode Material ◽

Methane Oxidation ◽

Solid Oxide ◽

Oxide Fuel ◽

Oxidation Activity

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Carbon isotope discrepancy between precambrian stromatolites and their modern analogs: Inferences from hypersaline microbial mats of the sinai coast

Origins of Life and Evolution of Biospheres ◽

10.1007/bf01808173 ◽

1985 ◽

Vol 15 (4) ◽

pp. 263-277 ◽

Cited By ~ 7

Author(s):

Manfred Schidlowski

Keyword(s):

Carbon Isotope ◽

Microbial Mats ◽

Hypersaline Microbial Mats

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Changes in carbon cycling under lowered sulfate conditions in hypersaline microbial mats as ascertained by stable carbon isotopes

10.1117/12.682000 ◽

2006 ◽

Author(s):

Cheryl A. Kelley ◽

Brad M. Bebout ◽

Leslie E. Prufert-Bebout ◽

Jason M. Smith

Keyword(s):

Carbon Cycling ◽

Carbon Isotopes ◽

Stable Carbon Isotopes ◽

Microbial Mats ◽

Stable Carbon ◽

Hypersaline Microbial Mats

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Abundance and Activity of Methanotrophic Bacteria in Littoral and Profundal Sediments of Lake Constance (Germany)

Applied and Environmental Microbiology ◽

10.1128/aem.01350-08 ◽

2008 ◽

Vol 75 (1) ◽

pp. 119-126 ◽

Cited By ~ 60

Author(s):

M. Rahalkar ◽

J. Deutzmann ◽

B. Schink ◽

I. Bussmann

Keyword(s):

Methane Oxidation ◽

Lake Constance ◽

Type I ◽

Sediment Depth ◽

Oxidation Activity ◽

Oxidation Rates ◽

Methane Oxidizing Bacteria ◽

Littoral Sediment ◽

Sediment Layers

ABSTRACT The abundances and activities of aerobic methane-oxidizing bacteria (MOB) were compared in depth profiles of littoral and profundal sediments of Lake Constance, Germany. Abundances were determined by quantitative PCR (qPCR) targeting the pmoA gene and by fluorescence in situ hybridization (FISH), and data were compared to methane oxidation rates calculated from high-resolution concentration profiles. qPCR using type I MOB-specific pmoA primers indicated that type I MOB represented a major proportion in both sediments at all depths. FISH indicated that in both sediments, type I MOB outnumbered type II MOB at least fourfold. Results obtained with both techniques indicated that in the littoral sediment, the highest numbers of methanotrophs were found at a depth of 2 to 3 cm, corresponding to the zone of highest methane oxidation activity, although no oxygen could be detected in this zone. In the profundal sediment, highest methane oxidation activities were found at a depth of 1 to 2 cm, while MOB abundance decreased gradually with sediment depth. In both sediments, MOB were also present at high numbers in deeper sediment layers where no methane oxidation activity could be observed.

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