Microbial Diversity and Distribution Patterns in Thermal Springs of the Baikal Region with Different Physicochemical Parameters

This is the first report on comparative characterization of the taxonomic diversity of microbial communities in the hydrotherms of the Baikal Region with various physicochemical conditions by molecular genetic methods. Comparative analysis of the composition of the dominant taxa revealed the differences depending on sampling site and sample type. The community of high-temperature areas with a water temperature of 55–73°С was shown to contain a high proportion of thermophilic bacteria Deinococcota, Acetothermia, Aquificota and, Armatimonadota; at temperatures below 35°С, the representatives of Bacteroidota were predominant. The members of the phyla Pseudomonadota and Bacillota were found within a wide temperature range of hydrotherms under study, which was indicative of their broad adaptive potential. In thermal and subthermal springs, the main factors determining the diversity of communities were mineralization, sodium, chloride and sulfate ion content, as well as temperature.