Background : Plants cultivation is hindered by root rot, a major disease caused by the soil-born fungi. The ginseng-cultivated soil is one of the nutritious habitats for soil-borne microorganisms. Bacteria from ginseng-cultivated soil can increase plant growth by supplying nutrients and hormones as well as protecting against pathogenic fungal infections and induced systematic resistance.
Methods and Results : The novel species DCY115T was isolated from ginseng-cultivated soil in Gochang province, Republic of Korea. The isolate was assigned to the genus Paraburkholderia due to its 16S rRNA gene sequence closely proximity to P. xenovorans LB400T (98.8%). Strain DCY115T is gram-negative, facultative aerobic, rod-shaped, non-flagellated, oxidase and catalase positive. The predominant isoprenoid quinone is ubiquinone Q-8. The genomic DNA G + C content is 61.3 mol%. Phenotypic tests and chemotaxonomic analysis place strain DCY115T in the genus Paraburkholderia. DNA-DNA hybridization values between strain DCY115T and closely related reference strains were lower than 51%. The DNA relatedness data in combination with phylogenetic and biochemical tests showed that strain DCY115T could not be assigned to any recognized species. Finally, strain DCY115T showed the plant growth promoting activities of siderophores production, phosphate solubilization, and antagonistic activity against root rot fungal pathogen Fusarium solani (KACC 44891T) and Cylindrocarpon destructans (KACC 44660T).
Conclusion : The results support the novel strain DCY115T as a potential biocontrol agent against root rot fungal pathogen within the genus Paraburkholderia for which the name Paraburkholderia panacihumi is proposed. The type strain is DCY115T (= KCTC52952T = JCM32099T).