The mineralogical and geochemical features of the Khoito-Gol ecosystem (fresh thermal waters–microorganisms–travertines) of the Baikal Rift Zone and the aspects of the interaction among its components were studied. The research has shown that the behavior, distribution, and accumulation of trace elements are determined mostly by the geochemical barriers of geologic and biologic genesis in the flowing-water habitat of bacteria of the Khoito-Gol spring. Formation of biominerals by different functional groups of its bacterial community is considered.

In the vast expanse of Baikal Siberia, indigenous nomadic animal groups have been conserved, grazing on pastures throughout the year. It is believed that the fecal microbiota of these diverse nomadic animal species is unique to each species and closely tied to their feeding environments. We conducted a pioneering comparative analysis of the taxonomic structure and the diversity of fecal microbiota in indigenous nomadic animals inhabiting Baikal Siberia. Our study encompassed 20 deer, 23 yaks, 24 camels, and 29 sheep, using high-throughput 16S rRNA gene profiling. In the fecal microbiota of these animals, we observed a predominant presence of the phyla Bacillota, Bacteroidota, and Verrucomicrobiota, collectively comprising over 88% of the microbial communities. Moreover, these proportions exhibited variations according to the host species. The unculturable Bacillota UCG-005 and UCG-010 are the key groups for all animals. However, at the genus level, distinctive compositions of fecal microbiota were discernible within each animal group. We identified a total of 37 dominant genera across the fecal samples from these four animal species. Principal component analysis (PCA) and cluster analysis demonstrated that the fecal microbiota composition clustered among individuals of the same animal species. Linear discriminant analysis effect size (LEfSe) indicated that camels exhibited higher abundances of the family Akkermansiaceae and the uncultured clostridial lineage UCG-010, while deer featured Lachnospiraceae; sheep had Ruminococcaceae; and yaks displayed Monoglobaceae, Bacteroidaceae, and methanogenic archaea from the family Methanobacteriaceae as distinctive marker taxa. Our studies showed that the studied nomadic animals feed mainly on plants belonging to the families Poaceae, Cyperaceae, Asteraceae, and Rosaceae. Our research indicated that the identity of the host species and, to a lesser degree, their diets and habitats, significantly shape the composition of fecal microbiota in these studied nomadic ruminant animals.

The structure and functional activity of the microbial communities formed under different environmental conditions of the Khoito-Gol mineral springs are investigated. The habitat of microorganisms in the Khoito-Gol springs is characterized by abundant hydrogen sulfide and intense circulation of sulfur with the participation of sulfate-reducing, thionic, colorless, and purple bacteria. The main terminal process of microbial destruction of organic matter is sulfate reduction.