MICROORGANISMS IN BOTTOM SEDIMENTS OF LAKE-BAIKAL AND ENVIRONMENTAL-CONDITIONS

The distribution of microorganisms, participating in cycles of carbon and sulfur depending on environmental conditions, was studied in botto m sediments of Lake Baikal. Abundance of studied groups of microorgani sms fluctuated within one order of magnitude. The values determined in the 1990s were comparable with data published earlier. This attested to the stable state of microflora in bottom sediments of Baikal. The r eplacement of one physiological group by others was observed along the core: saprophytes were outnumbered by thionic bacteria with depth, pu trefactive and sulfate-reducing bacteria developed more actively in su bsurface layers.