Degradation of organophosphorus pesticides mixtures using genetically engineered Escherichia coli BL21
利用基因工程菌BL21处理有机磷混合农药废水的研究

The suspended genetically engineered Escherichia coli BL21 and the PVA-immobilized cell were used in degrading of organophosphorus pesticides (OPs) mixtures. The strain rapidly degraded 1 000 mg/L of OPs mixtures, and parathion was the most favorite substrate of the five OPs investigated in this study. Malathion could not be degraded by the strain. The specific biodegradation rate was quite dissimilar for different kinds of OPs, which made the degradation process of different OPs to be described with different sorts of degradation kinetics. After immobilization, the degradation capacity were decreased dramatically, and the specific degradation rate of immobilized cell was only about 20% of that of suspended culture. The immobilized cells was also investigated with the long-term operation, and it retained 85% of degradation capability over 50-days of usage and storage. No undesirable softening of the gel or its dissolution were happened. Immobilized cells were more suitable for the wastewater treatment system than the suspended cells, although the specific degradation rates of suspended cultures were much higher.