Halolamina pelagica gen. nov., sp nov., a new member of the family Halobacteriaceae

Two extremely halophilic archaeal strains, TBN21(T) and TBN49, were isolated from the Taibei marine solar saltern near Lianyungang city, Jiangsu province, China. Cells of the two strains were pleomorphic and Gram-negative and colonies were red. Strains TBN21(T) and TBN49 were able to grow at 25-50 degrees C (optimum 37 degrees C), at 1.4-5.1 M NaCl (optimum 3.4-3.9 M) and at pH 5.5-9.5 (optimum pH 7.0-7.5) and neither strain required Mg2+ for growth. Cells lysed in distilled water and the minimal NaCl concentration to prevent cell lysis was 8% (w/v). The major polar lipids of the two strains were phosphatidic acid, phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, phosphatidylglycerol sulfate and eight glycolipids; three of these glycolipids (GL3, GL4 and GL5) were chromatographically identical to sulfated mannosyl glucosyl diether (S-DGD-1), galactosyl mannosyl glucosyl diether (TGD-1) and mannosyl glucosyl diether (DGD-1), respectively. Phylogenetic analysis revealed that strains TBN21(T) and TBN49 formed a distinct clade with their closest relative, Halobaculum gomorrense JCM 9908(T) (89.0-89.5% 16S rRNA gene sequence similarity). The DNA G+C contents of strains TBN21(T) and T3N49 were 64.8 and 62.7 mol%, respectively. DNA DNA hybridization between strains TBN21(T) and TBN49 was 90.1%. The phenotypic, chemotaxonomic and phylogenetic properties suggest that strains TBN21(T) and TBN49 represent a novel species in a new genus within the family Halobacteriaceae, for which the name Halolamina pelagica gen. nov., sp. nov. is proposed. The type strain of Halolamina pelagica is TBN21(T) (= CGMCC 1.10329(T) =JCM 16809(T)).