Sphingomonas humi sp. nov., isolated from soil.

A gram-negative, non-motile, non-spore-forming, small, orange, rod-shaped bacterium was isolated from soil in South Korea and characterized to determine its taxonomic position. Phylogenetic analysis based on 16S rRNA gene sequence examination revealed that strain PB323(T) belongs to the family Sphingomonadaceae. The highest degree of sequence similarity was found with Sphingomonas kaistensis PB56(T) (98.9%), followed by Sphingomonas astaxanthinifaciens TDMA-17(T) (98.3%). Chemotaxonomic characteristics (the G+C content of the genomic DNA 69.0 mol%, Q-10 quinone system, C(18:1) omega7c/omega9t/omega12t, C(16:1) omega7c/C(15:0) iso 2OH, C(17:1) omega6c, and C16:0 as the major fatty acids) corroborated assignment of strain PB323(T) to the genus Sphingomonas. Results of physiological and biochemical tests clearly demonstrate that strain PB323(T) represents a distinct species and support its affiliation with the genus Sphingomonas. Based on these data, PB323(T) (=KCTC 12341(T) =JCM 16603T =KEMB 9004-003(T)) should be classified as a type strain of a novel species, for which the name Sphingomonas humi sp. nov. is proposed.