Abstract
Thirteen novel strains - J2L1-78(T), J2P1-59(T), J22R24(T), J22R133(T), J22P168(T), J22P271(T), J22R187(T), J22R193(T), J2L1-63, J2R1-6, J22G21, J22G47, and J31P216 - were isolated from the rhizosphere of 20-year-old ginseng in Jilin Province, P.R. China. These strains were Gram-stain-negative, aerobic and rod-shaped. Phylogenetic analysis based on the 16S rRNA gene sequences indicated their affiliation to the genus Variovorax, with 98.8-99.6% sequence similarity to Variovorax ginsengisoli Gsoil 3165(T), Variovorax ureilyticus UCM-2(T) and Variovorax humicola UC38(T). Phylogenomic analysis demonstrated their distinctiveness from closely related species. Average nucleotide identity (ANI) values among these strains confirm their representation of eight distinct species; additionally, ANI and digital DNA-DNA hybridization values between these strains and their closest relatives were below 92.5 and 54.1%, respectively. Eight representative strains contained C(16 : 0), summed feature 3 (C(16 : 1) ω7c and/or C(16 : 1) ω6c) and C(17 : 0) cyclo as major fatty acids. Based on phenotypic, phylogenetic and genotypic data, these 13 strains comprise 8 novel species within the genus Variovorax, for which we propose the following names: Variovorax arabinosiphilus sp. nov. (J2L1-78(T)=CGMCC 1.60704(T)=KACC 23365(T)), Variovorax flavidus sp. nov. (J2P1-59(T)=CGMCC 1.60707(T)=KACC 23366(T)), Variovorax gracilis sp. nov. (J22R24(T)=CGMCC 1.61001(T)=KACC 23367(T)), Variovorax brevis sp. nov. (J22R133(T)=CGMCC 1.61263(T)=KACC 23368(T)), Variovorax jilinensis sp. nov. (J22P168(T)=CGMCC 1.64555(T)=KACC 23372(T)), Variovorax davisae sp. nov. (J22P271(T)=CGMCC 1.64593(T)=KACC 23373(T)), Variovorax saccharolyticus sp. nov. (J22R187(T)=CGMCC 1.64629(T)=KACC 23374(T)) and Variovorax fucosicus sp. nov. (J22R193(T)=CGMCC 1.64631(T)=KACC 23375(T)).