Halorubrum salinum sp. nov., isolated from a marine solar saltern

The halophilic archaeal strain GX71T was isolated from the Gangxi marine solar saltern near the Weihai city of Shandong Province, China. Cells of the strain were pleomorphic and lysed in distilled water, stained Gram-negative and formed red-pigmented colonies. Strain GX71T was able to grow at 25–45 °C (optimum 30 °C), in the presence of 1.7–4.8 M NaCl (optimum 2.6 M NaCl), with 0.005–0.7 M MgCl2 (optimum 0.05 M MgCl2) and at pH 5.5–9.5 (optimum pH 7.0–7.5). Cells lysed in distilled water and the minimal NaCl concentration to prevent cell lysis was 10 % (w/v). The major polar lipids of the strain were phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, phosphatidylglycerol sulfate, one major glycolipid chromatographically identical to sulfated mannosyl glucosyl diether (S-DGD-3) and an unidentified lipid was also detected. The 16S rRNA gene sequence of strain GX71T showed 94.0–97.0 % similarity to members of the genus Halorubrum of the family Halobacteriaceae. The rpoB′ gene sequence of strain GX71T was 87.3–93.4 % similarity to current members of the genus Halorubrum. The DNA G+C content of GX71T was 67.1 mol%. Strain GX71T showed low DNA–DNA relatedness with Halorubrum lipolyticum CGMCC 1.5332T, Halorubrum saccharovorum CGMCC 1.2147T, Halorubrum kocurii CGMCC 1.7018T and Halorubrum arcis CGMCC 1.5343T, the most closely related members of the genus Halorubrum. The phenotypic, chemotaxonomic and phylogenetic properties suggest that strain GX71T represents a novel species of the genus Halorubrum, for which the name Halorubrum salinum sp. nov. is proposed. The type strain is GX71T (= CGMCC 1.10458T = JCM 17093T).