Survey of alkaliphilic Bacillus-like resources in Kekexili, Qinghai

Abstract:

[Objective] To provide a foundation for new resource mining of the alkalophilic Bacillus-like species and development of microbial agents, we studied the species distribution and diversity of Bacillus-like isolated from soil samples in Kekexili of Qinghai Province. [Methods] Alkalophilic Bacillus species were isolated from soil samples using the cultural method on Horikoshi I medium and preliminarily identified based on 16S rRNA gene sequences. Then, strains with ability of protease-, cellulases- and xylanase-producing activity were screened using transparent zone method. [Results] A total of 66 strains of alkalophilic Bacillus species were obtained and identified as 22 species belonging to 6 genera, Bacillus, Gracilibacillus, Halobacillus, Jeotgalibacillus, Paenibacillus, and Psychrobacillus, by 16S rRNA gene sequences similarities analysis. The genus Bacillus was the dominant bacteria. There were 2 new potential species of alkalophilic Bacillus with 16S rRNA gene similarities 97.00% and 98.65%, respectively. Three enzymes-producing strains accounted for 95.00% of all isolates, including 55 strains with protease activity, 27 strains with cellulase activity, and 8 strains with xylanase. [Conclusion] There were rich resources of alkalophilic Bacillus species and abundant enzyme-producing strains in Kekexili of Qinghai Province, which provided a great potential of exploitation of alkaliphilic Bacillus species.