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

Abstract

A novel bacterium, designated DCY112T, 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 DCY45T (98.0%) and R. umsongensis GR24-2T (98.0%). Strain DCY112T 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-C15:0, iso-C17:0, and summed feature 9 (iso-C17:1 ω9c and/or 10-methyl-C16:0). 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 65.2mol%. DNA-DNA homology values between strain DCY112T and related strains were lower than 55%. The low DNA relatedness data in combination with phenotypic and genotypic tests indicated that strain DCY112T could not be assigned to a recognized species. Strain DCY112T showed antagonistic activity against the fungal pathogen Fusarium solani (KACC 44891T), which causes ginseng root rot. The results of this study support that strain DCY112T is a novel species belonging to the genus Rhodanobacter, for which the name Rhodanobacter ginsengiterrae is proposed. The type strain is DCY112T (= KCTC 62018T = JCM 32167T).