The research of relationship between microbiological factors with the distribution of anomalous methane fields and the presence of gas hydrate deposits using the example of two water areas in the northern part of Japan Sea

Our research focuses on the possibilities of using microorganisms as bioindicators in methane ecosystems in areas with gas hydrates (Area 1). We have conducted a study of the biodiversity of microorganisms and determined the physiological and biochemical properties of bacterial strains that can oxidize hydrocarbons isolated from the bottom sediments in the northern part of the Japan Sea for two areas: one with detected gas hydrates (Area 1) and one without the presence of gas hydrates (Area 2). Complex gas-geochemical, geological, and microbiological studies have been conducted in the waters of the northern Japan Sea, including the southern part of the Tatar Strait and the northern slope of Primorsky Krai. We used materials from marine expeditions: RV “Akademik Oparin” 54 (OP-54) in September–October 2017 and RV “Akademik M.A. Lavrentyev” 81 (LV-81) in May 2018. We used cultivation techniques to discover that members of the Nocardiaceae family from the Actinomycota phylum were associated with areas where gas hydrates had been detected. It was found that bacteria isolated from these areas were able to ferment a wider variety of carbohydrate substrates than those obtained from non-gas hydrate areas. A positive correlation was observed between the ability of these bacteria to break down carboxylic acids and their absence from gas hydrate-rich environments.