Detection of Thermophilic Methanotrophic Microbial Communities in the Water Column of the Bransfield Strait (Antarctica)

Abstract

The paper presents new findings of the thermophilic and mesophilic methanotrophic microorganisms in the study site in the Bransfield Strait (deeper than 1000 m). The gas-geochemical survey revealed single methane vent at a depth of 1397 m bss with a high methane concentration (43 nmol/l) in the bottom water layer. A methane saturated (10.29–14.46 nmol/l) water layer extended to a distance of 30–35 km around the central part of the methane anomaly. The studies of methane oxidation rate parameters revealed a significant microbiological filter within and around the methane venting site. The thermogenic origin of methane is addressed and confirmed by the associated cultivated forms of the thermophilic methanotrophic bacteria in the microbiological filter. The paper is based on original data obtained during the multidisciplinary expedition of the Russian Academy of Sciences (RV “Akademik Mstislav Keldysh,” cruise 79, December 2019 – May 2020, head of cruise Dr. Sci. E.G. Morozov).