Altererythrobacter Lauratis Sp. Nov. and Altererythrobacter Palmitatis Sp. Nov., Isolated from a Tibetan Hot Spring

Two Gram-negative, moderately thermophilic, yellow-pigmented, rod-shaped and motile bacterial strains, designated YIM 75003 T and YIM 75004 T , were isolated from sediment samples collected from the Tagejia hot spring in Tibet, western China. The taxonomic affiliation of the two strains was investigated by a polyphasic approach. Pairwise comparison of the 16S rRNA gene sequences showed that strains YIM 75003 T and YIM 75004 T are closely related to Altererythrobacter buctense M0322 T (97.2 and 97.1% respectively), while sharing 99.9% sequence similarity against each other. Optimum growth of the two strains was observed at 37–45 °C, pH 8.0 and in the presence of 1–6% NaCl (w/v). Their predominant respiratory quinone was found to be ubiquinone 10. The major fatty acids in both the strains were identified as summed feature 8 (C 18:1 ω 6 c and/or C 18:1 ω 7 c ) and summed feature 4 (C 17:1 anteiso B and/or iso I). Their major polar lipid profiles were found to be diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol and sphingoglycolipid. The DNA G+C contents of strains YIM 75003 T and YIM 75004 T were determined to be 61.3 and 60.1 mol%, respectively. The DNA-DNA hybridization values between strains YIM 75003 T and YIM 75004 T , and between the two strains and their closely related phylogenetic neighbour A. buctense M0322 T (=CGMCC 1.12871 T ) were less than 70%. Based on the morphological and physiological properties, phylogenetic analyses, chemotaxonomic characteristics and DNA–DNA relatedness values, the two strains can be distinguished from each other and from their phylogenetically closely related strain. Strains YIM 75003 T and YIM 75004 T are, therefore, considered to represent two novel species of the genus Altererythrobacter , for which the names Altererythrobacter lauratis sp. nov. (type strain YIM 75003 T = KCTC 52606 T = CCTCC AB2016268 T ) and Altererythrobacter palmitatis sp. nov. (type strain YIM 75004 T = KCTC 52607 T = CCTCC AB2016270 T ) are proposed.