Novosphingobium meiothermophilum sp. nov., isolated from a hot spring

A moderately thermophilic, aerobic, Gram-stain-negative, non-spore-forming, rod-shaped and yellow-pigmented bacterium, designated strain SYSU G00007^T, 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 G00007^T and other Novosphingobium species showed sequence similarities ranging from 93.7 to 97.9 %. Strain SYSU G00007^T showed highest sequence identity to Novosphingobium subterraneum DSM 12447^T (97.9 %). The average nucleotide identities and digital DNA-DNA hybridization values between strain SYSU G00007^T and its closely related phylogenetic neighbours were below 81 and 31 %, respectively, indicating that strain SYSU G00007^T represented a novel species of the genus Novosphingobium. The DNA G+C content of strain SYSU G00007^T was 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 : 0cyclo ω8c, summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) and C16 : 0. The results obtained from phylogenetic, chemotaxonomic and phenotypic analyses support the conclusion that strain SYSU G00007^T represents a novel species of the genus Novosphingobium, for which we proposed the name Novosphingobiummeiothermophilum sp. nov. The type strain is SYSU G00007^T (=KCTC 52672^T=CCTCC AB2017010^T).