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

Abstract

A non-spore-forming, Gram-negative, motile, rod-shaped, boron-accumulating bacterium isolated from soil was characterized by polyphasic taxonomy. The strain, designated BAM-48T, was positive for catalase and oxidase activities and grew at 4–37 °C, 0–1 % NaCl and pH 5–9. Comparative analysis of the 16S rRNA gene sequence demonstrated that the novel isolate BAM-48T was closely related to Variovorax paradoxus IAM 12373T (99.3 % sequence similarity), Variovorax soli GH9-3T (98.3 %) and Variovorax dokdonensis DS-43T (97.0 %). DNA–DNA hybridization values between strain BAM-48T and V. paradoxus NBRC 15149T, V. soli KACC 11579T and V. dokdonensis KCTC 12544T 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-48T contained C16 : 0 (36.1 %), C16 : 1 ω7c (21.4 %) and C17 : 0 cyclo (19.0 %) as the major fatty acids. Based on phenotypic, chemotaxonomic and phylogenetic data, strain BAM-48T 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-48T (=NBRC 103145T =KCTC 22010T).