Sphingomonas oligophenolica sp. nov., a halo- and organo-sensitive oligotrophic bacterium from paddy soil that degrades phenolic acids at low concentrations

The taxonomic position of a halo- and organo-sensitive, oligotrophic soil bacterium, strain S213^T was investigated. Cells were Gram-negative, non-motile, strictly aerobic, yellow-pigmented rods of short to medium length on diluted nutrient broth. When 0.1-0.4% (w/v) NaCl was added to diluted media composed of peptone and meat extract, growth was inhibited with increasing NaCl concentration and the cells became long aberrant forms. When 6 mM CaCl₂ was added, the cells grew quite normally and aberrant cells were no longer found at 0.1-0.5% (w/v) NaCl. Chemotaxonomically, strain S213^T contains chemical markers that indicate its assignment to the Sphingomonadaceae: the presence of ubiquinone Q-10 as the predominant respiratory quinone, C_18:1 and C_16:0 as major fatty acids, C_14:0 2-OH as the major 2-hydroxy fatty acid and sphingoglycolipids. 16S rRNA gene sequence analysis indicated that strain S213^T belongs to the genus Sphingomonas, exhibiting high sequence similarity to the 16S rRNA gene sequences of Sphingomonas mali IFO 15500^T (98.3%), Sphingomonas pruni IFO 15498^T (98.0%), Sphingomonas asaccharolytica IFO 15499^T (97.9%) and Sphingomonas echinoides DSM 1805^T (97.8%). The results of DNA-DNA hybridization experiments and its phenotypic characteristics clearly distinguished the strain from its nearest neighbours and demonstrate that strain S213^T represents a novel Sphingomonas species, for which the name Sphingomonas oligophenolica sp. nov. is proposed. The type strain is S213^T (=JCM 12082^T=CIP 107926^T).