Rhizobacter gummiphilus sp. nov., a rubber-degrading bacterium isolated from the soil of a botanical garden in Japan.

A rubber-degrading bacterium, the strain NS21, that was isolated from a soil sample in a botanical garden in Japan (Imai et al., 2011) was examined by phenotypic, phylogenetic and chemotaxonomic approaches to determine its taxonomic position. The strain NS21 was motile, possessing a single polar flagellum and a facultatively anaerobic straight rod. Analysis of the 16S rRNA and gyrB gene sequences of NS21 revealed a close relationship to the genus Rhizobacter. The predominant quinone type was Q-8. The G+C content of the NS21 genomic DNA was 70.8 mol%. The major fatty acids were C16:0, C17:0 cyclo, C18:1ω7c and C16:1ω7c and/or iso-C15:0 2-OH. C12:0 2-OH was present. The DNA-DNA hybridization experiments indicated that the DNA relatedness values of the strain NS21 to R. dauci H6(T) and R. fulvus Gsoil 322(T) were lower than 24%. The phenotypic characteristics showed obvious dissimilarities when compared to closely related species. On the basis of these taxonomic properties, a novel species is proposed as Rhizobacter gummiphilus sp. nov., with the strain NS21(T) (NBRC 109400(T), BCC 58006(T)) as the type strain. The emended description of the genus Rhizobacter was also presented.