Ornithinimicrobium panacihumi sp. nov., Antagonistic Bacteria Against Root Rot Fungal Pathogens, Isolated from Cultivated Ginseng Soil.

A Gram-positive bacterium (DCY118T) was isolated from ginseng-cultivated soil in Gochang-gun, Republic of Korea. This isolate was assigned to the genus Ornithinimicrobium and is closely related to Ornithinimicrobium kibberense K22-20T (98.8%), O. pekingense DSM 21552T (98.5%), O. algicola JC311T (98.2%), and O. humiphilum DSM 12362T (97.9%) based on 16S rRNA gene sequence analysis. However, strain DCY118T showed < 55% DNA-DNA homology with closely related reference strains. Cells were non-motile, non-sporulating, catalase- and oxidase-positive, aerobic, short rods, and cocci, and produced light-yellow, circular, and smooth colonies on TSA medium. MK-8(H4) was the predominant menaquinone. The major cellular fatty acids were iso-C15:0, anteiso-C15:0, and C16:0. The polar lipid profile consisted of diphosphatidylglycerol (DPG), phosphatidylglycerol (PG), phosphatidylinositol (PI), an unknown phospholipid (PL1), an unknown amino lipid (AL1), and unidentified polar lipids (L1-5). The genomic DNA G+C content was 71.1 mol%. The peptidoglycan contained L-ornithine as the diagnostic diamino acid. Whole-cell sugars were composed of glucose, arabinose, and xylose. Overall, data collected from phenotypic and genotypic tests during this study indicated that strain DCY118T could not be assigned to a recognized species. Strain DCY118T showed antagonistic activity against the fungal pathogens causing root rot in ginseng, i.e., Fusarium solani (KACC 44891T) and Cylindrocarpon destructans (KACC 44660T). The results from this study confirm the DCY118T strain as a new species within the genus Ornithinimicrobium, for which the name Ornithinimicrobium panacihumi is proposed. The type strain is DCY118T (=KCTC 39962T=JCM 32156T).