Rhizobium quercicola sp. nov., isolated from the leaf of Quercus variablis in China.

Abstract

Strain DKSPLA3T, a novel Gram-negative, catalase-positive, oxidase-positive, non-spore-forming, aerobic, non-nitrogen-fixing, non-motile bacterium was isolated from Quercus variablis leaf, in Zunyi, Guizhou, China. Growth occurred at 4-37°C (optimum 28°C), pH 4.0-9.0 (optimum pH 7.0) and up to 4.0% (w/v) NaCl (optimum under 2.0%, w/v). Phylogeny based on 16S rRNA gene indicated that strain DKSPLA3T was a novel species in the genus Rhizobium, which was supported by average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values. The predominant fatty acids of strain DKSPLA3T were C16:0, C18:1 ω7c and/or C18:1 ω6c and C18:1 ω7c 11-methyl. The major respiratory quinone was Q-10. Major polar lipids were diphosphatidyl glycerol (DPG), phosphatidyl glycerol (PG), phosphatidylethanolamine (PE), phosphatidylmonomethylethanolamine (PME), phosphatidylcholine (PC), two unidentified phospholipids (PL) and nine unidentified lipids (L). The genomic G + C content was 64.47mol%. Based on the phenotypic, phylogenetic and genotypic data, DKSPLA3T should be classified as a novel species in the genus Rhizobium, for which the name Rhizobium quercicola sp. nov. (KCTC 82843T = CFCC 16,707T) is proposed.