Halostagnicola kamekurae sp. nov., an extremely halophilic archaeon from solar salt

Abstract

A novel extremely halophilic archaeon, strain 194-10(T), was isolated from a solar salt sample imported into Japan from the Philippines. Strain 194-10(T) was pleomorphic, neutrophilic and mesophilic and required at least 10 % (w/v) NaCl but no MgSO(4) . 7H(2)O for growth; it exhibited optimal growth at 15 % (w/v) NaCl and 60 mM MgSO(4) . 7H(2)O. Strain 194-10(T) grew at 20-45°C (optimum, 30°C) and pH 6.0-9.0 (optimum, pH 6.5-7.0). The G+C content of its DNA was 59.8 mol%. 16S rRNA gene sequence analysis revealed closest proximity to Halostagnicola larsenii XH-48(T) (98.5 % similarity), the sole representative of the genus Halostagnicola. Polar lipid analysis revealed that strain 194-10(T) contained phosphatidylglycerol and phosphatidylglycerol phosphate methyl ester (the latter derived from both C(20)C(20) and C(20)C(25) archaeol) and several unidentified glycolipids. The results of DNA-DNA hybridization (20.7 % relatedness between Hst. larsenii JCM 13463(T) and strain 194-10(T)) and physiological and biochemical characteristics allowed differentiation of strain 194-10(T) from Hst. larsenii XH-48(T). Therefore, strain 194-10(T) represents a novel species of the genus Halostagnicola, for which the name Halostagnicola kamekurae sp. nov. is proposed, with the type strain 194-10(T) (=DSM 22427(T) =JCM 16110(T) =CECT 7536(T)).