Halostagnicola bangensis sp. nov., an alkaliphilic haloarchaeon from a soda lake

Abstract

An extremely haloalkaphilic archaeon, strain T26T, belonging to the genus Halostagnicola , was isolated from sediment of the soda lake Bange in the region of Tibet, China. Phylogenetic analysis based on 16S rRNA gene sequence similarities showed that strain T26T was closely related to Halostagnicola alkaliphila 167-74T (98.4 %), Halostagnicola larsenii XH-48T (97.5 %) and Halostagnicola kamekurae 194-10T (96.8 %). Strain T26T grew optimally in media containing 25 % (w/v) salts, at pH 9.0 and 37 °C in aerobic conditions. Mg2+ was not required for growth. The cells were motile, pleomorphic and Gram-stain-variable. Colonies of this strain were pink pigmented. Hypotonic treatment caused cell lysis. The polar lipids of the isolate consisted of C20C20 and C20C25 derivatives of phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester and minor phospholipids components. Glycolipids were not detected, in contrast to the two neutrophilic species of this genus. The genomic DNA G+C content of strain T26T was 60.1 mol% and DNA–DNA hybridization showed a relatedness of 19 and 17 % with Halostagnicola alkaliphila CECT 7631T and Halostagnicola larsenii CECT 7116T, respectively. The comparison of 16S rRNA gene sequences, detailed phenotypic characterization, polar lipid profile and DNA–DNA hybridization studies revealed that strain T26T belongs to the genus Halostagnicola , and represents a novel species for which the name Halostagnicola bangensis sp. nov. is proposed. The type strain is T26T ( = CECT 8219T = IBRC-M 10759T = JCM 18750T).