[Culturable bacterial diversity of the ancient salt deposits in the Kunming Salt Mine, P. R. China].

In order to understand the diversity of culturable bacteria, 44 bacteria strains inhabiting brines and salt crystals in the Kunming Salt Mine, P. R. China were isolated and cultured. Results showed that the numbers of the bacteria isolated from salt crystals (3.1 x 10(3) - 3.7 x 10(6) CFU/g) were higher than those from brines (1.3 - 6.3 x 10(3) CFU/L). A neighbor-joining tree of the partial 16S rDNA sequences (about 600bp of 5'-end) showed that 44 strains were phylogenetically clustered into 4 major groups and 44 distinct lineages or species (the similarities of 16S rDNA sequences <97%): 24 strains of Firmicutes (54.6%), 2 strains of alpha-Proteobacteria (4.6%), 4 strains of gamma-Proteobacteria (9.1%) and 14 strains of Actinobacteria (31.7%). Strains of the genus Bacillus (26.1% and 59.9%) were the most predominant microorganisms among brines and salt crystals. Additionally, seven potential novel species were found, based on the similarities of 16S rDNA sequences to those of previously published species, and seven strains with bioactivities against pathogenic microorganisms were isolated. The conclusion is that there are a number of novel species and bioactive strains, as well as great diversity in Kunming Salt Mine.