<Emphasis Type="Italic">Roseovarius tibetensis</Emphasis> sp. nov., a halophilic bacterium isolated from Lake LongmuCo on Tibetan Plateau

Two Gram-stain negative halophilic strains, designated as LM2^T and LM4, were isolated from Lake LongmuCo on Tibetan Plateau. These two strains were aerobic, catalaseand oxidase-positive, nonmotile and rod-shaped organisms. Phylogenetic analysis based on 16S rRNA gene sequences indicated that LM2^T and LM4 belong to the genus Roseovarius, with Roseovarius tolerans EL-172^T (97.3% and 97.4% 16S rRNA gene sequence similarity, respectively) and Roseovarius azorensis SSW084^T (95.5% and 95.6% 16S rRNA gene sequence similarity, respectively) as their closest neighbors. Q-10 was the sole respiratory quinone of these two strains. The major fatty acids were C_18:1ω7c/C_18:1ω6c, C_16:0, C_19:0 cyclo ω8c, and 11-methyl C_18:1ω7c. The polar lipids included phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phospholipid of unknown structure containing glucosamine, and unidentified aminolipid. The DNA G + C content was between 64.2 and 64.5 mol%. DNA-DNA hybridization showed 96.7% relatedness between LM2^T and LM4, 24.9% relatedness between LM2^T and R. tolerans EL-172^T, and 36.3% relatedness between LM4 and R. tolerans EL-172^T. Based on phylogenetic analysis, DNA-DNA hybridization, a range of physiological and biochemical characteristics, LM2^T and LM4 belong to the same species and were clearly distinguished from the type strains of the genus Roseovarius. It was evident that LM2^T and LM4 could be classified as a novel species of the genus Roseovarius, for which the name Roseovarius tibetensis sp. nov. is proposed. The type strain is LM2^T (= CGMCC 1.16230^T = KCTC 62028^T).