Protocols for Radiotracer Estimation of Methane Oxidation Rates at In Situ Methane Concentrations in Marine Sediments

2016 ◽  
pp. 277-303
Author(s):  
Ryan Sibert ◽  
Vladimir A. Samarkin ◽  
Samantha B. Joye
Keyword(s):  
Methane Oxidation ◽  
Marine Sediments ◽  
Oxidation Rates ◽  
Methane Concentrations

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

2008 ◽  
Vol 75 (1) ◽  
pp. 119-126 ◽  
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.

scholarly journals Methanotrophic activity and diversity in different <i>Sphagnum magellanicum</i> dominated habitats in the southernmost peat bogs of Patagonia

2012 ◽  
Vol 9 (1) ◽  
pp. 47-55 ◽  
Author(s):  
N. Kip ◽  
C. Fritz ◽  
E. S. Langelaan ◽  
Y. Pan ◽  
L. Bodrossy ◽  
...  
Keyword(s):  
Methane Oxidation ◽  
Northern Hemisphere ◽  
Water Levels ◽  
Peat Bogs ◽  
Oxidation Activity ◽  
Moss Species ◽  
Sphagnum Mosses ◽  
Methane Concentrations ◽  
Sphagnum Magellanicum

Abstract. Sphagnum peatlands are important ecosystems in the methane cycle. Methanotrophs living inside the dead hyaline cells or on the Sphagnum mosses are able to act as a methane filter and thereby reduce methane emissions. We investigated in situ methane concentrations and the corresponding activity and diversity of methanotrophs in different Sphagnum dominated bog microhabitats. In contrast to the Northern Hemisphere peat ecosystems the temperate South American peat bogs are dominated by one moss species; Sphagnum magellanicum. This permitted a species-independent comparison of the different bog microhabitats. Potential methane oxidizing activity was found in all Sphagnum mosses sampled and a positive correlation was found between activity and in situ methane concentrations. Substantial methane oxidation activity (23 μmol CH4 gDW−1 day−1) was found in pool mosses and could be correlated with higher in situ methane concentrations (>35 μmol CH4 l−1 pore water). Little methanotrophic activity (<0.5 μmol CH4 gDW−1 day−1) was observed in living Sphagnum mosses from lawns and hummocks. Methane oxidation activity was relatively high (>4 μmol CH4 gDW−1 day−1) in Sphagnum litter at depths around the water levels and rich in methane. The total bacterial community was studied using 16S rRNA gene sequencing and the methanotrophic communities were studied using a pmoA microarray and a complementary pmoA clone library. The methanotrophic diversity was similar in the different habitats of this study and comparable to the methanotrophic diversity found in peat mosses from the Northern Hemisphere. The pmoA microarray data indicated that both alpha- and gammaproteobacterial methanotrophs were present in all Sphagnum mosses, even in those mosses with a low initial methane oxidation activity. Prolonged incubation of Sphagnum mosses from lawn and hummock with methane revealed that the methanotrophic community present was viable and showed an increased activity within 15 days. The high abundance of methanotrophic Methylocystis species in the most active mosses suggests that these might be responsible for the bulk of methane oxidation.

scholarly journals Methane Monooxygenase Gene Transcripts as Quantitative Biomarkers of Methanotrophic Activity in Methylosinus trichosporium OB3b

2020 ◽  
Vol 86 (23) ◽  
Author(s):  
Egidio F. Tentori ◽  
Ruth E. Richardson
Keyword(s):  
Methane Oxidation ◽  
Methane Monooxygenase ◽  
Methane Emissions ◽  
Mrna Transcript ◽  
Methylosinus Trichosporium ◽  
Transcript Levels ◽  
Content Type ◽  
Oxidation Rates ◽  
Pure Cultures

ABSTRACT Methanotrophic microorganisms are characterized by their ability to oxidize methane. Globally they have a significant impact on methane emissions by attenuating net methane fluxes to the atmosphere in natural and engineered systems, though the populations are dynamic in their activity level in soils and waters. Methanotrophs oxidize methane using methane monooxygenase (MMO) enzymes, and selected subunit genes of the most common MMOs, specifically pmoA and mmoX, are used as biomarkers for the presence and abundance of populations of bacterial methanotrophs. The relative expression of these biomarker genes is dependent on copper-to-biomass ratios. Empirically derived quantitative relationships between methane oxidation biomarker transcript amounts and methanotrophic activity could facilitate determination of methane oxidation rates. In this study, pure cultures of a model type II methanotroph, Methylosinus trichosporium OB3b, were grown in hollow-fiber membrane bioreactors (HFMBR) under different steady-state methane oxidation conditions. Methanotroph biomass (DNA based) and methane oxidation biomarker mRNA transcript amounts were determined using quantitative PCR (qPCR) and reverse transcription-PCR (RT-qPCR), respectively. Under both copper-present and copper-limited conditions, per-cell pmoA mRNA transcript levels positively correlated with measured per-cell methane oxidation rates across 3 orders of magnitude. These correlations, if maintained across different methanotrophs, could prove valuable for inferring in situ oxidation rates of methanotrophs and understanding the dynamics of their impact on net methane emissions. IMPORTANCE Methanotrophs are naturally occurring microorganisms capable of oxidizing methane and have an impact on global net methane emissions. The genes pmoA and mmoX are used as biomarkers for bacterial methanotrophs. Quantitative relationships between transcript amounts of these genes and methane oxidation rates could facilitate estimation of methanotrophic activity. In this study, a strong correlation was observed between per-cell pmoA transcript levels and per-cell methane oxidation rates for pure cultures of the aerobic methanotroph M. trichosporium OB3b grown in bioreactors. If similar relationships exist across different methanotrophs, they could prove valuable for inferring in situ oxidation rates of methanotrophs and better understanding their impact on net methane emissions.

scholarly journals Methanotrophic activity and diversity in different <i>Sphagnum magellanicum</i> dominated habitats in the southernmost peat bogs of Patagonia

2011 ◽  
Vol 8 (5) ◽  
pp. 9357-9380 ◽  
Author(s):  
N. Kip ◽  
C. Fritz ◽  
E.S. Langelaan ◽  
Y. Pan ◽  
L. Bodrossy ◽  
...  
Keyword(s):  
Methane Oxidation ◽  
Northern Hemisphere ◽  
Water Levels ◽  
Peat Bogs ◽  
Oxidation Activity ◽  
Moss Species ◽  
Sphagnum Mosses ◽  
Methane Concentrations ◽  
Sphagnum Magellanicum

Abstract. Sphagnum peatlands are important ecosystems in the methane cycle. Methanotrophs living in and on the Sphagnum mosses are able to act as a methane filter and thereby reduce methane emissions. We investigated in situ methane concentrations and the corresponding activity and diversity of methanotrophs in different Sphagnum dominated bog microhabitats. In contrast to the Northern Hemisphere peat ecosystems the temperate South American peat bogs are dominated by one moss species; Sphagnum magellanicum. This permitted a species-independent comparison of the different bog microhabitats. Potential methane oxidizing activity was found in all Sphagnum mosses sampled and a positive correlation was found between activity and in situ methane concentrations. Substantial methane oxidation activity (23 μmol CH4 gDW−1 day−1) was found in pool mosses and could be correlated with higher in situ methane concentrations (>35 μmol CH4 l−1 pore water). Little methanotrophic activity (<0.5 μmol CH4 gDW−1 day−1) was observed in living Sphagnum mosses from lawns and hummocks. Methane oxidation activity was relatively high (>4 μmol CH4 gDW−1 day−1) in Sphagnum litter situated at depths around the water levels and rich in methane. The total bacterial community was studied using 16S rRNA gene sequencing and the methanotrophic communities were studied using a pmoA microarray and a complementary pmoA clone library. The methanotrophic diversity was similar in the different habitats of this study and surprisingly comparable to the methanotrophic diversity found in peat mosses from the Northern Hemisphere. The pmoA microarray data indicated that both alpha- and gammaproteobacterial methanotrophs were present in all Sphagnum mosses, even in those mosses with a low initial methane oxidation activity. Prolonged incubation of Sphagnum mosses from lawn and hummock with methane revealed that the methanotrophic community present was viable and showed an increased activity within 15 days. The high abundance of methanotrophic Methylocystis species in the most active mosses suggests that these might be responsible for the bulk of methane oxidation.

In situ mercaptosilane-assisted confinement of Pd nanoparticles in Beta for high-efficient methane oxidation

2021 ◽  
Author(s):  
Liling Zhang ◽  
Junfei Chen ◽  
Haolin Yang ◽  
Xiaohan Wang ◽  
Zebao Rui
Keyword(s):  
Methane Oxidation ◽  
Pd Nanoparticles ◽  
High Efficient

A Chloroflexi bacterium dechlorinates polychlorinated biphenyls in marine sediments under in situ-like biogeochemical conditions

2012 ◽  
Vol 209-210 ◽  
pp. 449-457 ◽  
Author(s):  
Giulio Zanaroli ◽  
Annalisa Balloi ◽  
Andrea Negroni ◽  
Luigimaria Borruso ◽  
Daniele Daffonchio ◽  
...  
Keyword(s):  
Polychlorinated Biphenyls ◽  
Marine Sediments
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