The anaerobic oxidation of methane (AOM) is a key biogeochemical process regulating methane emission from marine sediments into the hydrosphere. AOM is largely mediated by consortia of anaerobic methanotrophic archaea (ANME) and sulfate-reducing bacteria (SRB), and has mainly been investigated in deep-sea sediments. Here we studied methane seepage at four spots located at 12 m water depth in co...

Chemosynthetic ecosystems powered by microbial primary production are rare ‘hot spots’ of biological activity in the deep-sea characterized dense aggregations specially adapted animal species. Among settings where such systems have been found, serpentinite-hosted seep supported alkaline geofluid particularly understudied with just a few known sites worldwide. Mariana Forearc hosts world's only ...

Seep sediments are dominated by intensive microbial sulfate reduction coupled to the anaerobic oxidation of methane (AOM). Through geochemical measurements of incubation experiments with methane seep sediments collected from Hydrate Ridge, we provide insight into the role of iron oxides in sulfate-driven AOM. Seep sediments incubated with (13)C-labeled methane showed co-occurring sulfate reduct...

Anaerobic oxidation of methane (AOM) in marine sediments is an important global methane sink, but the physiological characteristics of AOM-associated microorganisms remain poorly understood. Here we report the cultivation of an AOM microbial community from deep-sea methane-seep sediment using a continuous-flow bioreactor with polyurethane sponges, called the down-flow hanging sponge (DHS) biore...

Vent and seep animals harness chemosynthetic energy to thrive far from the sun's energy. While symbiont-derived energy fuels many taxa, vent crustaceans have remained an enigma; these shrimps, crabs, and barnacles possess a phylogenetically distinct group of chemosynthetic bacterial epibionts, yet the role of these bacteria has remained unclear. We test whether a new species of Yeti crab, which...

Metazoan inhabitants of extreme environments typically evolved from forms found in less extreme habitats. Understanding the prevalence with which animals move into and ultimately thrive in extreme environments is critical to elucidating how complex life adapts to extreme conditions. Methane seep sediments along the Oregon and California margins have low oxygen and very high hydrogen sulfide lev...

The hydrothermal sediments of Guaymas Basin, an active spreading center in the Gulf of California (Mexico), are rich in porewater methane, short-chain alkanes, sulfate and sulfide, and provide a model system to explore habitat preferences of microorganisms, including sulfate-dependent, methane- and short chain alkane-oxidizing microbial communities. In this study, hot sediments (above 60°C) cov...

A mass occurrence of the thyasirid bivalve Thyasira montanita in a limestone bed, exposed at Punta Montañita on northern side Santa Elena peninsula southeastern Ecuador, is here identified as an ancient methane-seep deposit. The massive to nodular shows carbonate phases and microfabrics typical seep limestones, such banded botryoidal cements. Its δ13Ccarbonate values, low −52.6‰, suggest biogen...

Abstract. Soil bacteria rank among the most diverse groups of organisms on Earth and actively impact global processes carbon cycling, especially in emission greenhouse gases like methane, CO2 higher gaseous hydrocarbons. An abundant group soil are mycobacteria, which colonize various terrestrial, marine anthropogenic environments due to their impermeable cell envelope that contains remarkable l...