Sphingomonas daechungensis sp nov., isolated from sediment of a eutrophic reservoir

Strain CH15-11(T), isolated from a sediment sample taken from Daechung Reservoir, South Korea, during the late-blooming period of cyanobacteria, was found to be a Gram-stain-negative, non-motile, non-spore-forming, rod-shaped and aerobic bacterium. Strain CH15-11(T) grew optimally at pH 7 and 28-30 degrees C. According to a phylogenetic tree based on 16S rRNA gene sequences, strain CH15-11(T). belonged to the genus Sphingomonas and clustered with Sphingomonas sediminicola Dae 20(T), with which it shared the highest 16S rRNA gene sequence similarity (97.6%). Chemotaxonomic analysis showed that strain CH15-11(T) had characteristics typical of members of the genus Sphingomonas, such as the presence of sphingoglycolipid, ubiquinone 0-10 and sym-homospermidine. Plus, strain CH15-11(T) included summed feature 8 (C-18:1 omega 7c and/or C-18:1 omega 6c) and C-16:0 as the major fatty acids. The genomic DNA G+C content was 65.6 molok. Sequence data showed that strain CH15-11(T) was most closely related to Sphingomonas sediminicola Dae 20(T)(97.6%), Sphingomonas ginsengisoli Gsoil 634(T) (97.2%) and Sphingomonas jaspi TDMA-16(T) (97.0%). However, the DNA DNA relatedness values between strain CH15-11(T) and the most closely related type strains were within a range of 35-59%. Thus, based on the phylogenetic, phenotypic and genetic data, strain CH15-11(T) was classified as a member of the genus Sphingomonas as a representative of a novel species, for which the name Sphingomonas daechungensis sp. nov. is proposed. The type strain is CH15-11(T) (=KCTC 23718(T)=JCM 17887(T)).