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

Abstract

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 degrees C (optimum, 40 degrees 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, phosphatidylglycerolphosphate 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.