Bacillus natronophilus sp. nov., an alkaliphilic bacterium isolated from a soda lake

An alkaliphilic, moderately halophilic, heterotrophic, rod-shaped, spore-forming bacterium (M30 ) was isolated from a sediment sample collected from a soda lake (Lake Magadi, Tanzania). Strain M30 was strictly aerobic, catalase-positive, oxidase-negative and non-motile. Growth occurred at 12-43 °C (optimum, 25-30 °C), at pH 8.0-12 (optimum, pH 9.5-10) and at salinities of 0.5-15 % (w/v) NaCl (optimum 5 %). It utilized various sugars and organic acids as sole carbon sources and was positive for amylase, cellulase, gelatinase, protease and xylanase activities. The cell-wall peptidoglycan contained -diaminopimelic acid and the polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, one unidentified lipid and one unidentified phospholipid. The DNA G+C content was 48.9 mol%. The predominant menaquinone was MK-7 and the major fatty acids (>10 %) comprised anteiso-C , iso-C , and anteiso-C . Phylogenetic analysis based on 16S rRNA gene sequence affiliated M30 to the genus and showed the highest similarities to FJAT-45347 (96.4 %) and K1-5 (96.2 %). Based on the data from the current polyphasic study, M30 represents a novel species of the genus , for which the name sp. nov. is proposed. The type strain is M30 (=JCM 32118 =CGMCC 1.16739 =MCC 3010 ).