Halosimplex litoreum sp. nov., isolated from a marine solar saltern

A halophilic archaeal strain, YGH94T, was isolated from the Yinggehai marine solar saltern near the Shanya city of Hainan Province, China. Cells of the strain were observed to be short rods, stain Gram-negative and to form red-pigmented colonies on solid media. Strain YGH94T was found to grow at 25–50 °C (optimum 40 °C), at 0.9–4.8 M NaCl (optimum 3.1 M), at 0–1.0 M MgCl2 (optimum 0.05 M) and at pH 5.0–9.0 (optimum pH 7.5). The cells were found to lyse in distilled water and the minimal NaCl concentration to prevent cell-lysis was determined to be 5 % (w/v). The major polar lipids were identified as phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester and four major glycolipids (disulfated mannosyl glucosyl diether, sulfated mannosyl glucosyl diether and two unidentified glycolipids chromatographically identical to glycolipids in Halosimplex carlsbadense JCM 11222T). Strain YGH94T was found to possess two heterogeneous 16S rRNA genes (rrnA and rrnB) and both are related to those of Hsx. carlsbadense JCM 11222T (92.7–98.6 % similarities), Halosimplex pelagicum R2T (94.6–99.2 % similarities) and Halosimplex rubrum R27T (92.9–98.8 % similarities). The rpoB′ gene similarity between strain YGH94T and Hsx. carlsbadense JCM 11222T, Hsx. pelagicum R2T and Hsx. rubrum R27T are 95.4, 94.9 and 95.1 %, respectively. The DNA G+C content of strain YGH94T was determined to be 64.0 mol%. Strain YGH94T showed low DNA–DNA relatedness (35–39 %) with the current three members of the genus Halosimplex. The phenotypic, chemotaxonomic and phylogenetic properties suggest that strain YGH94T (=CGMCC 1.12235T = JCM 18647T) represents a new species of the genus Halosimplex, for which the name Halosimplexlitoreum sp. nov. is proposed.