The species composition of cyanobacteria from 12 lakes of Southern Transbaikal Region was studied. In the studied lakes, a total of 28 species of cyanobacteria were detected, including 10 species previously not retrieved from the lakes of Southern Transbaikal Region. The morphological and ecophysiological characteristics, as well as the phylogenetic position, of pure cyanobacterial cultures were determined. According to the results of 16S rRNA sequencing, the Cya 1, Cya 2, and Cya 10 cultures were identified as representatives of the genus Phormidium; the Cya 5 and Cya 6 cultures were assigned to the genus Nodularia. On the basis of its morphological properties, the Cya 4 culture was identified as Pseudanabaena frigida. The studied microorganisms were moderate alkaliphiles and could grow within a broad salinity range (0–100 g/l NaCl).

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.

A comprehensive research of water and cyanobacterial mats in Mogoysky and Shurindinsky thermal springs (Baikal rift zone) was carried out by hydrochemical, chemical, microbiological, and...

The structural features of a cyanobacterial mat from Lake Khilganta (Southeastern Transbaikal Region) developing at different values of salinity and pH were determined based on our long-term investiga

A hydrochemical study of the mineral hydrogen sulfide spring Bezymyanny, located on the coast of Lake Baikal in the Baikal region of the Republic of Buryatia, was carried out. Using the methods of liquid and gas-liquid mass spectrometry, the composition of allotropes of sulfur and organic polysulfides of the source, microbial mats and in their environment was studied. Polysulfides were monitored using previously developed concentration methods using solid-phase extraction and sulfur analysis in natural sulfide mineral waters. During the reduction of sulfates and the subsequent metabolism of hydrogen sulfide, various forms of sulfur are found in bottom sediments - sulfide, elemental, organic, sulfites and thiosulfates. The process of microbiological sulfate reduction is the main mechanism for the formation of reduced sulfur compounds. The presence of organic polysulfides simultaneously with elemental sulfur and hydrogen sulfide suggests that they are active balneological components of hydrogen sulfide mineral waters. The presence of a significant amount of hexasulfur in the water of microbial mats was observed compared to octasulfur in the source.

From the alkaline ecosystems of Zabaikalie, 12 monocultures of cyanobacteria belonging to the genera Anabaena, Leptolyngbya, Mastigocladus, Nodularia, Phormidium, Pseudanabaena and Synechococcus were isolated. The studied organisms showed themselves to be thermo- and alkaliphiles. The temperature optimum growth of cultures ranged from 40-55°C. Cultures were able to grow at alkaline pH values (8.5-9.5) and in a wide range of NaCl concentrations (0 to 100 g/l). Based on analysis of the 16S rRNA gene sequence, 5 strains of cyanobacteria were identified and described.