Abstract
A nonylphenol-assimilating bacterium isolated at a sewage-treatment plant in Tokyo was studied phenotypically, genotypically and phylogenetically. Analysis of the 16S rDNA sequence, the G+C content of the DNA (63 mol%) and the isoprenoid quinone composition, as well as the presence of sphingoglycolipid and the whole-cell fatty acid profile, revealed that the isolate is a member of the genus Sphingomonas. However, the sequence similarity of the 16S rDNA with that of known Sphingomonas spp. was found to be at most 96%, implying that the isolate is distinctive. Furthermore, the results of DNA--DNA hybridization experiments and its physiological characteristics clearly indicated that the isolate represents a new Sphingomonas species, for which the name Sphingomonas cloacae is proposed; strain S-3(T) (=JCM 10874(T)=IAM 14885(T)) is the type strain.