Structure and diversity of microbial salt crust in sulphate lake Gudzhirganskoye of the Barguzin depression (Buryatia)

Lake Gudzhirganskoe is a unique natural complex of extreme environmental conditions, where seasonal and daily temperature fluctuations, unstable water regime, significant fluctuations in salinity and water temperature, precipitation of salts on the surface of the lake, in turn, entail a change in the structure of the microbial community in the lake. In this study, we have used high-throughput sequencing of bacterial 16S rRNA gene amplicons to study diversity. Proteobacteria, Firmicutes and Bacteroidetes are the main phyla present in the studied salt crust samples. It has been shown that the microbial communities of the salt crusts of Lake Gudzhirganskoye consist of many highly adaptable organisms with heterogeneous physiological capabilities. Halophilic and moderately halophilic alkaliphilic bacteria are represented at the generic level, such as Halomonas, Rhodobaca, Rhodobaculum, etc. An interesting point is the discovery of a large proportion of 16S rRNA gene sequences that cannot be classified at the genera level, which indicates the presence of potential new representatives of the microbial world in this extreme ecosystem.