Abstract: tA microbial consortium named YL which can utilize pyrene as sole carbon and energy source was separated from the sediment of mangrove. YL showed high degradation capability with 92.09% of 50 mg/L pyrene within 21days. The plasmid was extracted from the pyrene degrading bacteria consortium YL by the improved method and transformed into Escherichia coli. Through the method of enrichment and culture， the transformed bacteria could utilize pyrene as sole carbon and energy sources. The biodegrading rate of pyrene was 85.69% within 21 days. While the E. coli only degrade 2.01% of pyrene within 21 days. Therefore, the transformed bacteria have a good pyrene degradation capability, and the plasmids carry the gene encoded for pyrene biodegradation.

Key words: mangrove； polycyclic aromatic hydrocarbons(PAHs)； plasmid, pyrene