Halopelagius inordinatus gen. nov., sp. nov., a new member of the family Halobacteriaceae isolated from a marine solar saltern

Abstract

Two extremely halophilic archaea, strains RO5-2Tand RO5-14, were isolated from Rudong marine solar saltern in Jiangsu, China. Cells of the two strains were pleomorphic, motile and stained Gram-negative. Colonies were red-pigmented. Strains RO5-2Tand RO5-14 were able to grow at 20–50 °C (optimum 37 °C), at 2.6–4.8 M NaCl (optimum 3.4–3.9 M NaCl), at 0.03–0.7 M MgCl2(optimum 0.5 M MgCl2) and at pH 5.5–8.0 (optimum pH 6.5–7.0). Cells lyse in distilled water and the minimal NaCl concentration to prevent cell lysis was 12 % (w/v). The major polar lipids of the two strains were phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester and two major glycolipids chromatographically identical to sulfated mannosyl glucosyl diether (S-DGD-1) and mannosyl glucosyl diether (DGD-1). The 16S rRNA gene sequences of strains RO5-2Tand RO5-14 showed 93.4–93.8 % similarity to the closest cultivated relative,Halosarcina pallida. The DNA G+C content of strains RO5-2Tand RO5-14 was 61.0 mol% and 59.9 mol%, respectively. The DNA–DNA relatedness between strains RO5-2Tand RO5-14 was 86.0 %. The phenotypic, chemotaxonomic and phylogenetic properties suggest that strains RO5-2Tand RO5-14 represent a novel species in a new genus within the familyHalobacteriaceae, for which the nameHalopelagius inordinatusgen. nov., sp. nov. is proposed. The type strain is RO5-2T(=CGMCC 1.7739T=JCM 15773T).