Paraburkholderia panacihumi sp. nov., an isolate from ginseng-cultivated soil, is antagonistic against root rot fungal pathogen.

Abstract

The novel species DCY115T was isolated from ginseng-cultivated soil in Gochang province, Republic of Korea. The isolated strain was assigned to the genus Paraburkholderia due to its 16S rRNA gene sequence proximity to Paraburkholderia xenovorans LB400T (98.8%), Paraburkholderia terricola LMG 20594T (98.4%), Paraburkholderia graminis C4D1MT (98.2%), Paraburkholderia rhynchosiae WSM3937T (98.1%), and Paraburkholderia phytofirmans PsJNT (98.1%). Strain DCY115T is gram-negative, facultative aerobic, rod-shaped, non-motile, non-flagellated, and oxidase and catalase positive. The predominant isoprenoid quinone of DCY115T is ubiquinone Q-8. The major cellular fatty acids are C16:0, cyclo-C17:0, cyclo-C19:0 ω8c, summed feature 3 (C16:1 ω7c and/or C16:1 ω6c) and summed feature 8 (C18:1 ω7c and/or C18:1 ω6c). The major polar lipids include diphosphatidylglycerol (DPG), phosphatidylglycerol (PG), phosphatidylethanolamine (PE), and an unknown amino lipid (AL1). 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 low 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 antagonistic activity against Fusarium solani (KACC 44891T) and Cylindrocarpon destructans (KACC 44660T), which are two root rot fungal pathogens of ginseng. In conclusion, the results in this study support strain DCY115T as a novel species within the genus Paraburkholderia for which the name Paraburkholderia panacihumi is proposed. The type strain is DCY115T (= KCTC 52952T = JCM 32099T).