A Gram-stain-negative, rod-shaped bacterial strain, designed RC4-10-4T, belonging to the genus Erythrobacter, was isolated from the East Rongbuk Glacier on the Tibetan Plateau. Strain RC4-10-4T grew optimally at pH 7.0, at 25 °C and in the presence of 2 % (w/v) NaCl. Summed feature 3 (C16 : 1 ω6c and/or iso-C15 : 0 2-OH), summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c) and C16 : 0 were the major fatty acids. The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, sphingoglycolipid and phosphatidylcholine. Carotenoid was detected in the cells. The DNA G+C content of the novel strain was 66.4 mol%. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain RC4-10-4T formed a distinct phylogenetic lineage within the cluster comprising Erythrobacter strains. Similarities between the 16S rRNA gene sequences of strain RC4-10-4T and the closely related strains Erythrobacter luteus KCTC 42179T, Erythrobacter gangjinensis KCTC 22330T, Erythrobacter odishensis KCTC 23981T and Erythrobacter atlanticuls KCTC 42697T were 98.0, 97.6, 97.5 and 97.2 %. The DNA-DNA hybridization values were 37.6, 15.4, 29.8 and 35.8 %, respectively. Based on the phenotypic and phylogenetic characteristics, strain RC4-10-4T represents a novel species of the genus Erythrobacter, for which the name Erythrobacter arachoides sp. nov. is proposed, with the type strain RC4-10-4T (=CGMCC 1.15507T=JCM 31277T).
Keywords: Erythrobacter; Proteobacteria; ice core.