Sphingobium fontiphilum sp. nov., isolated from a freshwater spring.

To investigate the biodiversity of bacteria in the spring water of the Chengcing Lake Park in Taiwan, a Gram-stain-negative, rod-shaped, non-motile, non-spore-forming and aerobic bacterial strain, designated strain Chen16-4(T), was isolated and characterized in a taxonomic study using a polyphasic approach. Phylogenetic analyses based on 16S rRNA gene sequences showed that the closest relatives of strain Chen16-4(T) were Sphingobium amiense YT(T), Sphingobium yanoikuyae GIFU 9882(T) and Sphingobium scionense WP01(T), with sequence similarities of 97.6, 97.1 and 97.0 %, respectively. A phylogenetic tree obtained with 16S rRNA gene sequences indicated that strain Chen16-4(T) and these three closest relatives formed an independent phylogenetic clade within the genus Sphingobium. The polar lipid pattern, the presence of spermidine and ubiquinone Q-10, the predominance of C18 : 1ω7c in the cellular fatty acid profile and the DNA G+C content also supported affiliation of the isolate to the genus Sphingobium. The DNA-DNA relatedness of strain Chen16-4(T) with respect to recognized species of the genus Sphingobium was less than 70 %. On the basis of the genotypic, chemotaxonomic and phenotypic data, strain Chen16-4(T) represents a novel species in the genus Sphingobium, for which the name Sphingobium fontiphilum sp. nov. is proposed. The type strain is Chen16-4(T) ( = BCRC 80308(T) = LMG 26342(T) = KCTC 23559(T)).