Screening of PAHs-degrading bacterial strains and determination of their capability in degrading PAHs

Eight PAHs-degrading bacterial strains were screened out from the enriched culture with PAHs-contaminated soils in Benxi City of Liaoning Province,Northeast China,and the capability of the strains in degrading phenanthrene,phyrene,and benzo[a]pyrene with an initial concentration of 50,50,and 5 mg·L-1 in medium was determined after 28-day incubation at 28 ℃. Among the strains screened out,B3 showed the best degrading effect,with the degradation rate of phenanthrene,phyrene,and benzo[a]pyrene being 88.4%,54.0%,and 68.4%,while the degradation rate of these compounds by the mixed 8 strains was 87.7%,35.3%,and 42.0%,respectively. The strain B3 was identified as Pseudomonas sp.,based on its physiological and biochemical characteristics and the sequence analysis of 16S rRNA.