Roseovarius gahaiensis sp. nov., isolated from Gahai Saline Lake, PR China.

Abstract

A Gram-stain-negative, aerobic, non-motile and ovoid- to rod-shaped bacterial strain, designated GH877T, was isolated from a water sample of Gahai saline lake in Qaidam Basin,PR China. The isolate grew at 5-45 °C, pH 6.0-9.0 (optima, 37 °C and pH 7.5) and with 0.5-20 % (w/v) NaCl (optimum, 2.0 %). The neighbour-joining phylogenetic tree of 16S rRNA gene sequences showed that strain GH877T belonged to the genus Roseovarius, and had highest 16S rRNA gene sequence similarity of 97.7 % to Roseovarius pacificus 81-2T, followed by Roseovarius halotolerans HJ50T (97.5 %) and Roseovarius litoreus GSW-M15T (96.8 %). Genome sequencing revealed a genome size of 3 378 519 bp and a G+C content of 59.8 mol %. Up-to-date bacterial core gene set analysis indicated that strain GH877T represents one independent lineage with R. pacificus DSM29589T. The average nucleotide identity values of GH877T with R. pacificus 81-2T and R. halotolerans HJ50T are 80.7 and 77.3 %, respectively. In silico DNA-DNA hybridization values between strain GH877T and R. pacificus 81-2T and R. halotolerans HJ50T are 23.2 and 20.0 %, respectively. Q-10 was the predominant respiratory quinone and summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c) and C16 : 0 were the major cellular fatty acids. The polar lipids of strain GH877T consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine and two unidentified phosphoglycolipids. Based on polyphasic taxonomic analysis, strain GH877T is proposed to represent a novel species of the genus Roseovarius, for which the name Roseovarius gahaiensis sp. nov. is proposed. (type strain GH877T=CGMCC 1.13971T=KCTC 72576T).