Biodegradation of benzo[a]pyrene by the mixed culture of Bacillus cereus and Bacillus vireti isolated from the petrochemical industry.

Polycyclic aromatic hydrocarbons are a group of compounds that pose threat to humans and animal life. Methods to reduce the amount of PAHs in the environment are continuously being sought. The bacterial consortium capable of utilizing benzo(a)pyrene as the sole source of carbon and energy was isolated from petrochemical soil. The isolates were identified as Bacillus cereus and Bacillus viretibased on morphological characterization, and 16S rDNA gene sequence analysis. About 58.98% of benzo(a)pyrene at concentration of 500 mg l(-1) in mineral salts medium were removed by bacterial consortium. GC mass spectral analysis showed the presence of metabolite cis-4-(7-hydroxypyren-8-yl)-2-oxobut-3enoic acid. The results indicate that the bacterial consortium is a new bacterial resource for biodegrading benzo(a)pyrene and might be used for bioremediation of sites heavily contaminated by benzo[a]pyrene and its derivatives.