CYCLOCLASTICUS PUGETII GEN-NOV, SP-NOV, AN AROMATIC HYDROCARBON-DEGRADING BACTERIUM FROM MARINE-SEDIMENTS

Three heterotrophic bacterial strains were isolated from different loc ations in Puget Sound, Washington, by using biphenyl as the principal carbon source. These strains grow by using a limited number of organic compounds, including the aromatic hydrocarbons naphthalene, phenanthr ene, anthracene, and toluene, as sole carbon sources. These aerobic, g ram-negative rods are motile by means of single polar flagella. Their 16S rRNA sequences indicate that they are all members of the gamma sub division of the Proteobacteria. Their closest known relatives are the genera Methylobacter and Methylomonas (genera of methane-oxidizing bac teria), uncultured sulfur-oxidizing symbionts found in marine inverteb rates, and clone FL5 containing 16S ribosomal DNA amplified from an en vironmental source. However, the Puget Sound bacteria do not use metha ne or methanol as a carbon source and do not oxidize reduced sulfur co mpounds. Furthermore, a 16S rRNA base similarity comparison revealed t hat these bacteria are sufficiently different from other bacteria to j ustify establishment of a new genus. On the basis of the information s ummarized above, we describe a new genus and species, Cycloclasticus p ugetii, for these bacteria; strain PS-1 is the type strain of C. puget ii.