Variovorax dokdonensis sp nov., isolated from soil

A Gram-negative, motile and oval- or rod-shaped bacterial strain, DS-43(T), was isolated from soil from Dokdo, Korea, and its taxonomic position was investigated by using a polyphasic approach. The strain grew optimally at pH 7.0-8.0 and at 30 degrees C in the presence of 0.5% (w/v) NaCl. Strain DS-43(T) had Q-8 as the predominant ubiquinone and C-16:0, C-16:1 omega 7c and/or iSO-C-15:0 2-OH, C-18:1 omega 7c and C-17:0 cyclo as the major fatty acids, which are consistent with the corresponding data for the type strain (KCTC 12459(T)) of Variovorax paradoxus. The DNA G + C content was 66.0 mol%. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain DS-43(T) was most closely related to Variovorax paradoxus, the only recognized species of the genus. The level of 16S rRNA gene sequence similarity between strain DS-43(T) and V. paradoxus AM 12373(T) was 97.3%. DNA-DNA relatedness data and differential phenotypic properties demonstrated that strain DS-43(T) is distinguishable from V. paradoxus. On the basis of phenotypic, phylogenetic and genetic data, it is proposed that strain DS-43(T) (= KCTC 12544(T) = CIP 108838(T)) be classified in the genus Variovorax as a member of a novel species, Variovorax dokdonensis sp. nov.