Rhabdothermincola salaria sp. nov., a novel actinobacterium isolated from a saline lake sediment

Abstract

An actinobacterium, designated strain EGI L10124T, was isolated from saline lake sediment collected in Xinjiang province, PR China. The taxonomic position of the isolate was determined based on polyphasic taxonomic and phylogenomic analyses. Phylogenetic analysis and 16S rRNA gene sequence similarities indicated that strain EGI L10124T formed a distinct clade with Rhabdothermincola sediminis SYSU G02662T, with a shared sequence identity of 95.2 %. The novel isolate could be distinguished from species in the genus Rhabdothermincola by its distinct phenotypic, physiological and genotypic characteristics. The cells of strain EGI L10124T were aerobic, Gram-stain-positive and short rod-shaped. Optimal growth conditions of strain EGI L10124T on marine agar 2216 were registered at pH 8.0 at 37 °C. In addition, meso-diaminopimelic acid was the diagnostic diamino acid in the cell-wall peptidoglycan. The major respiratory quinone was MK-9 (H8), while the major fatty acids were iso-C16 : 0, C17 : 0 and C16 : 0. The polar lipids included diphosphatidylglycerol, phosphatidylinositol mannoside and phosphatidylinositol. Based on the genome sequence of strain EGI L10124T, it appears that the G+C content of the novel isolate was 71.8 mol%. According to our data, strain EGI L10124T represents a new species of the genus Rhabdothermincola , for which the name Rhabdothermincola salaria sp. nov. is proposed. The type strain of the proposed novel isolate is EGI L10124T (=CGMCC 1.19113T=KCTC 49679T).