Two bacterial strains, CP173-2T and CP1DT, were isolated from biological soil crusts (BSCs) collected in the Colorado Plateau, USA. Both strains were pigmented, Gram-negative, non-motile rods and produced abundant mucus. They contained C16:0, C1'8:1ω7c and C14:0 2-OH as the predominant cellular fatty acids, ubiquinone-10 as the isoprenoid quinone and sphingoglycolipid. Based on the above characteristics, the isolates were assigned to the family Sphingomonadaceae; 16 rRNA gene signature nucleotides placed them within the genus Sphingomonas. Strains CP173-2T and CP1DT had a 16S rRNA gene sequence similarity of 96.7% with each other and 91.6-98.9% sequence similarity with other species in the genus, indicating that they represent two separate, and possibly novel, species. The closest species to strains CP173-2T and CP1DT were, respectively, Sphingomonas dokdonensis (98.9% gene sequence similarity) and Sphingomonas panni (97.9%). However, strain CP173-2T exhibited a DNA-DNA relatedness of only 32.5 % with the type strain of S. dokdonensis. Similarly, the DNA-DNA relatedness between strain CP1DT and the type strain of S. panni was only 18%. Phenotypic characterization supported this low relatedness. On the basis of this evidence, we propose that the new strains represent two novel species, for which the names Sphingomonas mucosissima sp. nov. (with type strain CP173-2T = ATCC BAA-1239T = DSM 17494T) and Sphingomonas desiccabilis sp. nov. (with type strain CP1 DT = ATCC BAA-1041T = DSM 16792T) are proposed.
|Original language||English (US)|
|Number of pages||7|
|Journal||International Journal of Systematic and Evolutionary Microbiology|
|State||Published - May 2007|
ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics