Variovorax boronicumulans sp. nov., a boron-accumulating bacterium isolated from soil.

A non-spore-forming, Gram-negative, motile, rod-shaped, boron-accumulating bacterium isolated from soil was characterized by polyphasic taxonomy. The strain, designated BAM-48(T), was positive for catalase and oxidase activities and grew at 4-37 degrees C, 0-1% NaCl and pH 5-9. Comparative analysis of the 16S rRNA gene sequence demonstrated that the novel isolate BAM-48(T) was closely related to Variovorax paradoxus IAM 12373(T) (99.3% sequence similarity), Variovorax soli GH9-3(T) (98.3%) and Variovorax dokdonensis DS-43(T) (97.0%). DNA-DNA hybridization values between strain BAM-48(T) and V. paradoxus NBRC 15149(T), V. soli KACC 11579(T) and V. dokdonensis KCTC 12544(T) were only 49.1, 25.4 and 24.6%, respectively. The major respiratory quinone was ubiquinone 8 (Q-8). The DNA G+C content was 71.2 mol%. Strain BAM-48(T) contained C(16:0) (36.1%), C(16:1)omega7c (21.4%) and C(17:0) cyclo (19.0%) as the major fatty acids. Based on phenotypic, chemotaxonomic and phylogenetic data, strain BAM-48(T) should be classified as a member of a novel species in the genus Variovorax, for which the name Variovorax boronicumulans sp. nov. is proposed. The type strain is BAM-48(T) (=NBRC 103145(T) =KCTC 22010(T)).