Sphingopyxis chilensis sp. nov., a chlorophenol-degrading bacterium that accumulates polyhydroxyalkanoate, and transfer of Sphingomonas alaskensis to Sphingopyxis alaskensis comb. nov.

The taxonomic position of a chlorophenol-degrading bacterium, strain S37T, was investigated. The 16S rDNA sequence indicated that this strain belongs to the genus Sphingopyxis, exhibiting high sequence similarity to the 16S rDNA sequences of Sphingomonas alaskensis LMG 18877T (98.8%), Sphingopyxis macrogoltabida LMG 17324T (98.2%), Sphingopyxis terrae IFO 15098T (95%) and Sphingomonas adhaesiva GIFU 11458T (92%). These strains (except Sphingopyxis terrae IFO 15098T, which was not investigated) and the novel isolate accumulated polyhydroxyalkanoates consisting of 3-hydroxybutyric acid and 3-hydroxyvaleric acid from glucose as carbon source. The G + C content of the DNA of strain S37T was 65.5 mol%. The major cellular fatty acids of this strain were octadecenoic acid (18 : 1omega7c), heptadecenoic acid (17 : 1omega6c) and hexadecanoic acid (16 : 0). The results of DNA-DNA hybridization experiments and its physiological characteristics clearly distinguished the novel isolate from all known Sphingopyxis species and indicated that the strain represents a novel Sphingopyxis species. Therefore, the species Sphingopyxis chilensis sp. nov. is proposed, with strain S37T (=LMG 20986T =DSM 14889T) as the type strain. The transfer of Sphingomonas alaskensis to the genus Sphingopyxis as Sphingopyxis alaskensis comb. nov. is also proposed.