The oxidation of methane with sulfate is an important microbial metabolism in the global carbon cycle. In marine methane seeps, this process is mediated by consortia of anaerobic methanotrophic archaea (ANME) that live in syntrophy with sulfate-reducing bacteria (SRB). The underlying interdependencies within this uncultured symbiotic partnership are poorly understood. We used a combination of r...

In recent years, methane (CH4) has received increasing scientific attention because it is the most abundant non-CO2 atmospheric greenhouse gas (GHG) and controls numerous chemical reactions in the troposphere and stratosphere. However, there is much that is unknown about CH4 sources and sinks and their evolution over time. Here we show that near-surface cavities in the uppermost vadose zone are...

Abstract. Several foraminifera are deposit feeders that consume organic detritus (dead particulate material with entrained bacteria). However, the role of such in benthic food web remains understudied. Foraminifera feeding on methanotrophic bacteria, which 13C-depleted, may cause negative cytoplasmic and/or calcitic δ13C values. To test whether foraminiferal diet includes methanotrophs, we perf...

ABSTRACT The microbial key players at methane seeps are methanotrophic archaea and sulfate-reducing bacteria. They form spherical aggregates jointly mediate the sulfate-dependent anaerobic oxidation of (SD–AOM: CH4 + SO42? ? HCO3? HS? H2O), thereby inducing precipitation authigenic seep carbonates. While carbonates constitute valuable archives for molecular fossils SD–AOM-mediating microbes, no...

Microbially mediated anaerobic oxidation of methane (AOM) moderates the input of methane, an important greenhouse gas, to the atmosphere by consuming methane produced in various marine, terrestrial, and subsurface environments. AOM coupled to sulfate reduction has been most extensively studied because of the abundance of sulfate in marine systems, but electron acceptors otherthan sulfate are mo...

Post-treatment of anaerobic wastewater was undertaken to biologically oxidize dissolved methane, with the aim of preventing methane emission. The performance of dissolved methane oxidation and competition for oxygen among methane, ammonium, organic matter, and sulfide oxidizing bacteria were investigated using a lab-scale closed-type down-flow hanging sponge (DHS) reactor. Under the oxygen abun...

Lipase from Candida rogusa was immobilized on MCM-41 mesoporous molecular sieves in a trapped aqueous-organic biphase system for the resolution of racemic naproxen methyl ester. It was interesting that the activity and enantioselectivity of the immobilized lipase were improved significantly relative to the free enzyme. The proportion of water (ml)/support (g) has a dramatic influence on the act...

The global methane cycle includes both terrestrial and atmospheric processes and may contribute to feedback regulation of the climate. Most oxic soils are a net sink for methane, and these soils consume approximately 20 to 60 Tg of methane per year. The soil sink for atmospheric methane is microbially mediated and sensitive to disturbance. A decrease in the capacity of this sink may have contri...

As in other cold seeps, the dominant bivalves in mud volcanoes (MV) from the Gulf of Cadiz are macrofauna belonging to the families Solemyidae (Acharax sp., Petrasma sp.), Lucinidae (Lucinoma sp.), Thyasiridae (Thyasira vulcolutre) and Mytilidae (Bathymodiolus mauritanicus). The delta(13)C values measured in solemyid, lucinid and thyasirid specimens support the hypothesis of thiotrophic nutriti...

Hopanoids methylated at the C-3 position are a subset of bacterial triterpenoids that are readily preserved in modern and ancient sediments and in petroleum. The production of 3-methylhopanoids by extant aerobic methanotrophs and their common occurrence in modern and fossil methane seep communities, in conjunction with carbon isotope analysis, has led to their use as biomarker proxies for aerob...