Isolation and Identification of Chlorpyrifos Degrading Strains and Optimization of Degradation Conditions

Objective: Isolating and screening the chlorpyrifos-degrading strains, and studying their growth characteristics and degradation characteristics, the location of the strain’s degrading enzymes and the broad-spectrum degradation studies. Methods: Taken from the farmland soil around Changbai Mountain, the inorganic salt medium with chlorpyrifos as carbon source was used to enrich the microorganisms in the soil, and the genus was determined by morphological observation, physiological and biochemical identification and 16SrRNA molecular sequencing. The location of the chlorpyrifos-degrading enzyme of the strain, the determination of the broad-spectrum degradation of the strain against dichlorvos, omethoate, methyl parathion, hydrocarbamate, acetochlor, and atrazine, and the degradation of the strain by single factor experiment and orthogonal test. The chlorpyrifos conditions are optimized. Results: A chlorpyrifos-degrading bacterium Pseudomonas aeruginosa AY-1 was screened and initially identified as Pseudomonas aeruginosa. Its chlorpyrifos-degrading enzyme was an intracellular enzyme. Phosphorus, acetochlor, and atrazine had good broad-spectrum degradation ability. After orthogonal test optimization, the optimal degradation conditions were 35 ℃, pH=8, and the substrate concentration was 100 mg/L, the degradation efficiency was 75.09%. Conclusion: The strain Pseudomonas aeruginosa AY-1 had a high ability to degrade chlorpyrifos, and had a certain broad-spectrum degradation effect on organophosphorus pesticides. It would have a great application potential in the remediation of organic phosphorus pesticides polluted environment and the removal of organophosphorus pesticide residues on the surface of food crops.