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 °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 Q-10 and sym-homospermidine. Plus, strain CH15-11(T) included summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) and C16 : 0 as the major fatty acids. The genomic DNA G+C content was 65.6 mol%. 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 http://www.genebank.go.kr/eng/microbe/microbe_search_view.jsp?sStrainsn=4602Sphingomonas 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)).