Bacillus alkalicola sp. nov., An Alkaliphilic, Gram-Positive Bacterium Isolated from Zhabuye Lake in Tibet, China

A Gram-positive, alkaliphilic bacterium, designated strain Zby6T, was isolated from Zhabuye Lake in Tibet, China. The strain was able to grow at pH 8.0–11.0 (optimum at pH 10.0), in 0–8 % (w/v) NaCl (optimum at 3 %, w/v) and at 10–45 °C (optimum at 37 °C). Cells of the isolate were facultatively anaerobic and spore-forming rods with polar flagellum. The predominant isoprenoid quinone was MK-7, and its cell wall peptidoglycan contained meso-diaminopimelic acid. The major cellular fatty acids were iso-C15:0, C16:0 and anteiso-C15:0. The major polar lipids consisted of phosphatidylglycerol, diphosphatidylglycerol, and phosphatidylethanolamine. The genomic DNA G+C content of the isolate was 38.9 mol%. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain Zby6T was a member of the genus Bacillus and most closely related to Bacillus cellulosilyticus DSM 2522T (97.7 % similarity). The DNA–DNA relatedness value between strain Zby6T and B. cellulosilyticus DSM 2522T was 59.2 ± 1.8 %. Comparative analysis of genotypic and phenotypic features indicated that strain Zby6T represents a novel species of the genus Bacillus, for which the name Bacillus alkalicola sp. nov. is proposed; the type strain is Zby6T (=CGMCC 1.10368T = JCM 17098T = NBRC 107743T).