[Biodegradation of Pyrene by Intact Cells and Spores of Brevibacillus brevis]

Biodegradation characteristics of pyrene by intact cells and spores of Brevibacillus brevis were investigated. The results revealed that the degradation efficiency of 1 mg · L(-1) pyrene by B. brevis intact cells reached 53% within 5 d. Four hydroxy metabolites were detected by LC-MS/MS during the degradation of pyrene by intact cells and intracellular enzymes, including 1-hydroxy-pyrene, 9- phenanthrol, α-naphthol and β-naphthol. The amount of products first increased and then declined in the degradation system with intact cells, while the macromolecular metabolites showed a continuous accumulation tendency in the degradation system with intracellular enzymes, proving that some degrading enzymes of B. brevis could be induced by the products generated during the degradation, and then the enzymes induced could further degrade these degradation products. The amount of cells germinated from spores in MSM containing pyrene was 1.5 x 10(9) cells · L(-1), and the degradation rate of pyrene (1 mg · L(-1)) within 5 d reached 15%.