Halostella salina gen. Nov., sp. nov., an extremely halophilic archaeon isolated from solar salt

A novel halophilic archaeon designated strain CBA1114^T was isolated from solar salt in the Republic of Korea. Strain CBA1114^T, cells of which were coccoid and Gram-stain-negative, grew in the presence of 15–30 % (w/v) NaCl (optimum, 20 %) and at 20–50 °C (optimum, 40 °C) and pH 7.0–9.0 (optimum, pH 8.0). Strain CBA1114^T required Mg²⁺ for growth. Strain CBA1114^T had three 16S rRNA genes, rrnA, rrnB and rrnC; levels of similarity between the sequences were 99.7–99.9 %. The 16S rRNA gene sequence of strain CBA1114^T showed 91.7 % similarity to that of Haloterrigena thermotolerans PR5^T. In multilocus sequence analysis (MLSA), five housekeeping genes, atpB, EF-2, radA, rpoB’ and secY, were found to be closely related to those of the members of the genera Halorientalis(89.7 % similarity of the atpB gene sequence), Halomicroarcula(91.9 %, EF-2), Haloterrigena(85.4 %, radA), Natronoarchaeum (89.2 %, rpoB’) and Natrinema(75.7 %, secY). A phylogenetic tree generated from the results of MLSA of the five housekeeping genes showed that strain CBA1114^T was closely related to species of the genus Halorientalis in the family Halobacteriaceae. The major polar lipids were identified as phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester and unidentified lipids. The G+C content of the genomic DNA of strain CBA1114^T was 68.1 mol%. According to the results of phylogenetic, phenotypic and chemotaxonomic analyses, we designate strain CBA1114^T (=JCM 30111^T=KCTC 4206^T) as the type strain of Halostella salina gen. nov., sp. nov., a novel species of a new genus within the family Halobacteriaceae.