Solirubrobacter phytolaccae sp. nov., an endophytic bacterium isolated from roots of Phytolacca acinosa Roxb.

Abstract

A Gram-staining-positive, strictly aerobic, rod-shaped, non-motile, non-spore-forming bacterial strain, designated GTGR-8(T), which formed white colonies, was isolated from roots of Phytolacca acinosa Roxb. collected from Taibai Mountain in Shaanxi Province, north-west China. Strain GTGR-8(T) grew optimally at 28-30 °C, at pH 7.0-8.0 and in the absence of NaCl. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain GTGR-8(T) was a member of the genus Solirubrobacter and was closely related to Solirubrobacter pauli B33D1(T) (98.9% similarity), Solirubrobacter ginsenosidimutans BXN5-15(T) (97.0%) and Solirubrobacter soli Gsoil 355(T) (96.9%). No other recognized bacterial species showed more than 94.2% 16S rRNA gene sequence similarity to the novel isolate. The only respiratory quinone of strain GTGR-8(T) was MK-7(H4) and the major fatty acids (>5%) were iso-C16 : 0, C18 : 1ω9c, C17 : 1ω8c, C18 : 3ω6c (6,9,12) and C17 : 1ω6c. The DNA G+C content was 71.0 mol%. DNA-DNA relatedness for strain GTGR-8(T) with respect to its closest relatives, S. pauli KCTC 9974(T) and S. ginsenosidimutans KCTC 19420(T), was 52.5 and 24.5%, respectively. Based on phenotypic, phylogenetic and genotypic data, strain GTGR-8(T) is considered to represent a novel species in the genus Solirubrobacter, for which the name Solirubrobacter phytolaccae sp. nov. is proposed. The type strain is GTGR-8(T) ( = CCTCC AB 2013011(T) = KCTC 29190(T)).