Variovorax defluvii sp. nov., isolated from sewage

Abstract

A polyphasic taxonomic study was carried out on 2C1-b T and 2C-21, two strains isolated from sewage flowing into River Geumho in Korea. Cells of the two strains were Gram-negative, nonspore-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 22010 T, Variovorax dokdonensis KCTC 12544 T, Variovorax ginsengisoli KCTC 12583 T, Variovorax paradoxus ATCC 17713 T and Variovorax soli KACC 11579 T 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-b T and 2C1-21 were 65.5 and 65.2 mol%, respectively. Phenotypic and chemotaxonomic data [Q-8 as the major ubiquinone; C 16: 0, summed feature 4 (C 16: 1 ω7c and/or iso-C 15: 0 2-OH), C 17: 0 cyclo and summed feature 7 (C 18: 1ω7c and/or ω9t and/or ω12t) as major fatty acids] supported the affiliation of strains 2C1-b T and 2C-21 to the genus Variovorax. Based on evidence derived from this polyphasic analysis, it is proposed that strains 2C1-b T and 2C1-21 represent a novel species for which the name Variovorax defluvii sp. nov. is proposed; the type strain is 2C1-b T (=KCTC 12768 T=JCM 17804 T).