Comparison of Benzo［a］pyrene-Degrading Activities between Olleya sp. ITB9 Isolated from Tokyo Bay and Other Type Strains of the Genus Olleya.

Benzo［a］pyrene (BaP) is one of the strongest carcinogenic compounds among polycyclicaromatic hydrocarbons (PAHs) .We previously identified the ITB9 strain of Olleya species, which shows BaP-degrading activity; our report was the first about BaP degradation by the genus Olleya. In this study, BaP-degradation efficiency by ITB9 was about 50% when the strain was suspended in 20 ml of L9 liquid medium with 100 μg/ml BaP and 0.2 M NaCl, with pH 8.0, and incubated at 25℃ for 5 days. Under the same conditions, all four type strains (O. marilimosa CIP108537, O. aquimaris KCTC22661, O. namhaensis KCTC23673, and O. algicola KCTC22024) also showed BaP-degrading activities, at efficiencies ranging from 49% to 63%. Olleya sp. ITB9 and O. aquimaris KCTC22661 were found to be in the same clade in the phylogenetic tree of the genus Olleya, given that the homology of 16S rRNA gene sequences between ITB9 and KCTC22661 was 99.77%.