Abstract

A moderately thermophilic, aerobic, Gram-stain-negative, non-spore-forming, rod-shaped and yellow-pigmented bacterium, designated strain SYSU G00007T, was isolated from a hot spring slurry sample. Optimum growth was observed at 37–45 °C and pH 7. Pairwise comparison of the 16S rRNA gene sequence of strain SYSU G00007Tand otherNovosphingobiumspecies showed sequence similarities ranging from 93.7 to 97.9 %. Strain SYSU G00007Tshowed highest sequence identity toNovosphingobium subterraneumDSM 12447T(97.9 %). The average nucleotide identities and digital DNA–DNA hybridization values between strain SYSU G00007Tand its closely related phylogenetic neighbours were below 81 and 31 %, respectively, indicating that strain SYSU G00007Trepresented a novel species of the genusNovosphingobium. The DNA G+C content of strain SYSU G00007Twas 64.3 % (genome). The major respiratory quinone was ubiquinone Q-10. The polar lipid profile included diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, two sphingoglycolipids, two unidentified phospholipids, two unidentified aminophospholipids and two unidentified polar lipids. Spermidine was the only polyamine detected. The major fatty acids were C19 : 0cycloω8c, summed feature 8 (C18 : 1ω7cand/or C18 : 1ω6c) and C16 : 0. The results obtained from phylogenetic, chemotaxonomic and phenotypic analyses support the conclusion that strain SYSU G00007Trepresents a novel species of the genusNovosphingobium, for which we proposed the nameNovosphingobiummeiothermophilumsp. nov. The type strain is SYSU G00007T(=KCTC 52672T=CCTCC AB2017010T).