We present stable isotope and geochemical data from four sediment cores from west of Prins Karls Forland (ca. 340 m water depth), offshore western Svalbard, recovered from close to sites of active methane seepage, as well as from shallower water depths where methane seepage is not presently observed. Our analyses provide insight into the record of methane seepage in an area where ongoing ocean ...

Methane oxidation associated with the belowground tissues of a common aquatic macrophyte, the burweed Sparganium eurycarpum, was assayed in situ by a chamber technique with acetylene or methyl fluoride as a methanotrophic inhibitor at a headspace concentration of 3 to 4%. Acetylene and methyl fluoride inhibited both methane oxidation and peat methanogenesis. However, inhibition of methanogenesi...

The anaerobic oxidation of methane (AOM) in the marine subsurface is a significant sink for methane in the environment, yet our understanding of its regulation and dynamics is still incomplete. Relatively few groups of microorganisms consume methane in subsurface environments--namely the anaerobic methanotrophic archaea (ANME clades 1, 2 and 3), which are phylogenetically related to methanogeni...

in this trial, the effect of different levels of echum amoneum (ea) (0.3, 30, 300 or 3000 µl) on in vitro ruminal fermentation characteristics and methane production was assessed. the parameters studied were in vitro gas production (ivgp), methane production, ammonia (nh3-n) concentration, in vitro organic matter degradability (ivomde), partitioning factor (pf) (the ratio of substrate truly deg...

The Gas Push–Pull Test (GPPT) is a tool for measuring in situ soil processes including methane oxidation. To quantify methane oxidation, methane and non-reactive gases selected based on transport behaviour similar to methane, were injected into soil above a petroleum hydrocarbon contaminated aquifer and gas samples were extracted over time. The rate of loss of methane was compared to the loss o...

Methanotrophs in enrichment cultures grew and sustained atmospheric methane oxidation when supplied with methanol. If they were not supplied with methanol or formate, their atmospheric methane oxidation came to a halt, but it was restored within hours in response to methanol or formate. Indigenous forest soil methanotrophs were also dependent on a supply of methanol upon reduced methane access ...

We review the reservoirs of methane clathrates that may exist in the different bodies of the Solar System. Methane was formed in the interstellar medium prior to having been embedded in the protosolar nebula gas phase. This molecule was subsequently trapped in clathrates that formed from crystalline water ice during the cooling of the disk and incorporated in this form into the building blocks ...

e role of the microbial processes governing methane emissions from tundra ecosystem is receiving increasing attention. Recently, cooperation between methanotrophic bacteria and submerged Sphagnum was shown to reduce methane emissions but also to supply CO2 for photosynthesis for the plant. Although this process was shown to be important in the laboratory, the differences that exist in methane ...

Methane emissions in the Arctic are important, and may be contributing to global warming. While methane emission rates from Arctic lakes are well documented, methods are needed to quantify the relative contribution of active layer groundwater to the overall lake methane budget. Here we report measurements of natural tracers of soil/groundwater, radon, and radium, along with methane concentratio...