Molecular Bacterial Diversity in Water at the Deep-Well Monitoring Site Tomsk-7

Bacterial diversity was studied in a water sample collected from a depth of 290-324 m below the land surface from the monitoring site S15 near the city of Tomsk, Siberia, Russia. In order to overcome the problems of culturability of bacteria, we applied a direct molecular approach based on PCR amplification and cloning of the 16S rDNA of the members of the natural bacterial communities. 65% of the cloned sequences were almost identical to the 16S rRNA genes of Dechlorosoma sp. belonging to the Rhodocyclus group of b-subclass of Proteobacteria. Relatively high was the number of the sequences which shared high identities with the 16S rRNA genes of some cultured g-Proteobacteria (6.9%), a-Proteobacteria (4.6%) and with the sequences of mostly uncultured members of Cytophaga/Flavobacterium/Bacteroides (5.4%), Actinobacteria (4.6%) and Planctomycetales (2.3 %). The rest of the retrieved sequences were clustered in small groups, each containing about 1 % of the total number of clones, and they matched with 16S rDNA sequences of Bacillales, Holophaga/Acidobacteria, Nitrospira, and d-Proteobacteria, respectively.