Isolation and biological characterization of the bacteria from the alkaline soil of Hoh Xil

Abstract:

Hoh Xil, an extremophile environment situated at the Yushu Tibetan Autonomous Region in southwest Qinghai, is one of the most primitive and well-preserved natural environment on earth. The microbial diversity in this area is poorly known till date. In this present study an attempt has been made to selectively isolate the alkalophilic microorganisms in 12 salina soil samples from Hoh Xil, by using five different medium. As a result, 5 alkaliphilic or salkaline tolerant isolates were obtained. 16S rRNA gene sequence analysis showed that 4 strains belonged to 4 different genera, such as Planomicrobium, Kocuria, Aerococcus, and Bacillus. Another strain, designated CPCC 100153 was the nearest to the genus Geomicrobium, showing the 16S rRNA gene sequence similarity level of 93.5 % to the strain Geomicrobium halophilum BH1T. Based on the phenotypic characteristics, physiological and biochemical tests, chemotaxonomic analysis and genotypic data, we found that the strain CPCC 100153T not only shared some common characteristics with the alkaliphilic or salkaline tolerant species of the related genus in the family Bacillaceae but also clearly differentiated from them. Therefore, we propose the strain CPCC 100153T represents a novel genus and species within the family Bacillaceae.