Diversity of bacteria isolated from saline alkali soil of Bishkek region in Kyrgyzstan

Abstract:

[Objective] The diversity of culturable bacteria in saline alkali soil of Bishkek region in Kyrgyzstan was detected by Physiological test and phylogenetic analysis. [Methods] Using the screening media (R2A, TSB, 1/4 x NA and Gause No. 1 medium) containing 5% NaCl, salt resistant strains were screened. Based on morphological characteristics involving gram staining, salt resistance, growth temperature, pH tolerance and enzyme production performance, we researched the taxonomic identity and genetic variability of strains isolated by ARDRA classification map. [Results] One hundred and twenty salt-tolerant strains were isolated from Bishkek saline soil samples. Restriction enzyme Hae III was applied in ARDRA and 19 operational taxonomic units (OTUs) were assigned on the basis of the ARDRA patterns. Each OTU was randomly chosen for 16S rRNA gene sequencing. The phylogenetic analysis on the basis of 16S rRNA gene homology showed that all isolates affiliated to 17 genera, belonged to Firmicutes, Proteobacteria and Actinobacteria. Two of the isolates showed less affilation with known taxon (<97% sequence similarity) and may represent novel taxa. [Conclusion] The results suggest that the salt-tolerant bacteria are abundant, and some unknown taxa maybe exist in Bishkek region.