Halolamina sediminis sp. nov., an extremely halophilic archaeon isolated from solar salt

An extremely halophilic archaeal strain, halo-7T, was isolated from brine sediment of the Gomso solar saltern, Republic of Korea. Cells of strain halo-7T were pleomorphic, stained Gram-negative, lysed in distilled water and formed red-pigmented colonies. Strain halo-7T grew in the range of 25-45°C (optimum 37-40°C), pH 6.5-9.5 (optimum pH 7.0-8.0), 15-30% (w/v) NaCl (optimum, 20-25%), and 0.05-0.5 M MgCl2 (optimum 0.1-0.3 M). The minimal NaCl concentration to prevent cell lysis of strain halo-7T was 10% (w/v). The major polar lipids of the isolate were phosphatidylglycerol, phosphatidylglycerolphosphate methyl ester, an unidentified phospholipid, an unidentified lipid, and two unidentified glycolipids. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain halo-7T is closely related to the members of the genus Halolamina, Halolamina salina WSY15-H3T (98.7% 16S rRNA gene sequence similarity), Halolamina pelagica TBN21T (98.2%) and Halolamina rubra CBA1107T (97.4%). The genomic DNA G+C content determined for strain halo-7T (68.0 mol%) was slightly higher than those of H. salina JCM 18549T and H. rubra CBA1107T. DNA-DNA hybridization values between strain halo-7T and reference strains were < 25%. Based on phenotypic, chemotaxonomic and phylogenetic properties, we describe a novel species of the genus Halolamina, represented by strain halo-7T, for which we propose the name Halolamina sediminis sp. nov. The type strain is halo-7T ( = JCM 30187T = CECT 8739T).