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

Two halophilic archaeal strains, YC20(T) 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 NaCI I-1 and 0.5-95 g MgCl2 I-1 for growth at the optimum growth temperature of 37 degrees 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 YC20(T) 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 YC20(T) and XD15 were 65.8 mol% and 65.4 mol%, respectively. The DNA-DNA hybridization value between strain YC20(T) 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 YC20(T) and XD15 represent a novel species of the genus Halobellus, for which the name Halobellus inorclinatus sp. nov. is proposed. The type strain is YC20(T) (=CGMCC 1.12120(T)=JCM 18361(T)) and the other strain is XD15 (=CGMCC 1.12236=JCM 18648).