Rhodanobacter ginsengiterrae sp nov., an antagonistic bacterium against root rot fungal pathogen Fusarium solani, isolated from ginseng rhizospheric soil

A novel bacterium, designated DCY112(T), was isolated from the rhizospheric soil of a ginseng-cultivated field in Gochang-gun, Republic of Korea. Based on 16S rRNA gene sequence analysis, this isolate was assigned to the genus Rhodanobacter and is closely related to Rhodanobacter soli DCY45(T) (98.0%) and R. umsongensis GR24-2(T) (98.0%). Strain DCY112(T) is Gram-negative, catalase- and oxidase-positive, aerobic, non-motile, rod-shaped, and produces yellow-pigmented colonies on R2A medium. Q-8 was the predominant respiratory quinone. The major cellular fatty acids were iso-C-15:0, iso-C-17:0, and summed feature 9 (iso-C(17:1)9c and/or 10-methyl-C-16:0). The major polar lipids were phosphatidylglycerol (PG), phosphatidylethanolamine (PE), an unknown amino lipid (AL1), and an unidentified polar lipid (L3). The genomic DNA G+C content was 65.2 mol%. DNA-DNA homology values between strain DCY112(T) and related strains were lower than 55%. The low DNA relatedness data in combination with phenotypic and genotypic tests indicated that strain DCY112(T) could not be assigned to a recognized species. Strain DCY112(T) showed antagonistic activity against the fungal pathogen Fusarium solani (KACC 44891(T)), which causes ginseng root rot. The results of this study support that strain DCY112(T) is a novel species belonging to the genus Rhodanobacter, for which the name Rhodanobacter ginsengiterrae is proposed. The type strain is DCY112(T) (=KCTC 62018(T)=JCM 32167(T)).