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

An extremely halophilic archaeal strain YJ-50-S2T was isolated from Yangjiang marine solar saltern, China. Cells were pleomorphic, stained Gram-negative and formed red-pigmented colonies on agar plates. Strain YJ-50-S2T was able to grow at 25-50 °C (optimum 37 °C), with 0.9-4.8 M NaCl (optimum 2.6 M NaCl) and 0-1.0 M MgCl2 (optimum 0.03 M MgCl2), and at pH 5.0-9.5 (optimum pH 7.5). The cells lysed in distilled water and the minimal NaCl concentration to prevent cell lysis was 5 % (w/v). The 16S rRNA gene and rpoB' gene of strain YJ-50-S2T were phylogenetically related to the corresponding genes of Salinigranum rubrum GX10T (97.0 % and 90.5 % similarities, respectively). The major polar lipids of strainYJ-50-S2T were phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, and two major glycolipids chromatographically identical to sulfated mannosyl glucosyl diether and mannosyl glucosyl diether, respectively. Several unidentified glycolipids were also detected. The DNA G+C content of strain YJ-50-S2T was 65.2 mol%. The phenotypic, chemotaxonomic and phylogenetic properties suggested that strain YJ-50-S2Trepresents a novel species of the genus Salinigranum, for which the name Salinigranum salinum sp. nov. is proposed. The type strain is YJ-50-S2T (=CGMCC 1.12572T=JCM 30033T).