Variovorax defluvii sp. nov., isolated from sewage

Abstract

A polyphasic taxonomic study was carried out on 2C1-bT and 2C-21, two strains isolated from sewage flowing into River Geumho in Korea. Cells of the two strains were Gram-negative, non-spore-forming, motile and oval or rod-shaped. Comparative 16S rRNA gene sequence studies showed a clear affiliation of these two isolates with members of the Betaproteobacteria ; they were most closely related to Variovorax boronicumulans KCTC 22010T, Variovorax dokdonensis KCTC 12544T, Variovorax ginsengisoli KCTC 12583T, Variovorax paradoxus ATCC 17713T and Variovorax soli KACC 11579T showing 16S rRNA gene sequence similarities of 97.4–98.8 % with these strains and shared 100 % similarity with each other. The genomic DNA G+C contents of strains 2C1-bT and 2C1-21 were 65.5 and 65.2 mol%, respectively. Phenotypic and chemotaxonomic data [Q-8 as the major ubiquinone; C16 : 0, summed feature 4 (C16 : 1ω7c and/or iso-C15 : 0 2-OH), C17 : 0 cyclo and summed feature 7 (C18 : 1ω7c and/or ω9t and/or ω12t) as major fatty acids] supported the affiliation of strains 2C1-bT and 2C-21 to the genus Variovorax . Based on evidence derived from this polyphasic analysis, it is proposed that strains 2C1-bT and 2C1-21 represent a novel species for which the name Variovorax defluvii sp. nov. is proposed; the type strain is 2C1-bT ( = KCTC 12768T = JCM 17804T).