Methanogenic microbial communities from bottome sediments of Lake Baikal, associated with gas and oil discharges

In the near future, the increase in methane emissions into the atmosphere can play a major role in creating a greenhouse effect on the Earth. In this connection, study of the magnitude and seasonal dynamics of methane emissions from various natural ecosystems, as well as the influence of environmental and geochemical factors on the composition and functioning of methanogenic communities are relevant. One of the important natural sources of methane is the bottom sediments of freshwater ecosystems. Bottom sediments of the largest freshwater Lake Baikal are the source of methane of all three known genetic types, biogenic, thermogenic and endogenous. However, gas of biogenic origin is the most common in the lake. Unlike the bottom sediments of most other stratified lakes, where methane is mainly formed along the acetoclastic pathway, 75-100% of methane in the sediments of the deep-water part of Lake Baikal is formed from H2 and CO2. To date, the character of this phenomenon remains unknown. In this regard, this project is aimed at identifying the main environmental factors that determine the non-standard ratio of the contribution of methanogenesis pathways to the total methane production in the bottom sediments of Lake Baikal.