Halobellus inordinatus sp. nov., from a marine solar saltern and an inland salt lake of China

Two halophilic archaeal strains, YC20T and XD15, were isolated from a marine solar saltern and an inland salt lake in China. Both had pleomorphic cells that lysed in distilled water, stained Gram-negative and formed red-pigmented colonies. They were neutrophilic, requiring at least 100 g NaCl l−1 and 0.5–95 g MgCl2 l−1 for growth at the optimum growth temperature of 37 °C. The major polar lipids of the two strains were phosphatidylglycerol (PG), phosphatidylglycerol phosphate methyl ester (PGP-Me), phosphatidylglycerol sulfate (PGS) and two major glycolipids chromatographically identical to sulfated mannosyl glucosyl diether (S-DGD-1) and mannosyl glucosyl diether (DGD-1), respectively. Trace amounts of two unidentified glycolipids were also detected. The 16S rRNA gene sequences of the two strains were 99.5 % identical and showed 94.0–95.9 % similarity to the most closely related members of the genus Halobellus of the family Halobacteriaceae . The rpoB′ gene sequence similarity between strains YC20T and XD15 was 98.2 % and these sequences showed 89.6–92.8 % similarity to those of the most closely related members of the genus Halobellus . The DNA G+C contents of strains YC20T and XD15 were 65.8 mol% and 65.4 mol%, respectively. The DNA–DNA hybridization value between strain YC20T and strain XD15 was 92 %, and the two strains showed low DNA–DNA relatedness to members of the genus Halobellus . The phenotypic, chemotaxonomic and phylogenetic properties suggest that strains YC20T and XD15 represent a novel species of the genus Halobellus , for which the name Halobellus inordinatus sp. nov. is proposed. The type strain is YC20T ( = CGMCC 1.12120T = JCM 18361T) and the other strain is XD15 ( = CGMCC 1.12236 = JCM 18648).