Hyphomicrobium album sp. nov., isolated from mountain soil and emended description of genus Hyphomicrobium

A soil bacterium, designated XQ2T, was isolated from Lang Mountain in Hunan province, P. R. China. The strain is Gram stain negative, facultative anaerobic, and the cells are motile and rod-shaped. The 16S rRNA gene sequence of strain XQ2T shared the highest similarities with Hyphomicrobium sulfonivorans S1T (97.1%), Pedomicrobium manganicum ACM 3038T (95.9%) and Hyphomicrobium aestuarii DSM 1564T (95.4%) and grouped with H. sulfonivorans S1T. The average nucleotide identity (ANI) values and the DNA–DNA hybridization (dDDH) values between strain XQ2T and H. sulfonivorans S1T were 86.6% and 55.4% respectively. Strain XQ2T had a genome size of 3.91 Mb and the average G+C content was 65.1%. The major fatty acids (> 5%) were C18:1ω6c, C18:1ω7c, C19:0 cyclo ω8c, C16:0 and C18:0. The major respiratory quinone was Q-9 (82.8%) and the minor one was Q-8 (17.2%). The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, unidentified phospholipid and two unidentified lipids. On the basis of phenotypic, chemotaxonomic and phylogenetic characteristics, strain XQ2T represents a novel species of the genus Hyphomicrobium, for which the name Hyphomicrobium album sp. nov. is proposed. The type strain is XQ2T (= KCTC 82378T = CCTCC AB 2020178T). The genus description is also emended.