Effect of laccase extracted from fungi using food industrial residues as culture medium on degradation of chlorpyrifos in solution

Chlorpyrifos is one of the most widely used organophosphate insecticides in the world. Its extensive application has resulted in water and soil pollution and even disruption of biogeochemical cycles. In the current study, laccase extracted from the fungus Trametes versicolor using apple pomace as culture medium was used for the degradation of chlorpyrifos in solution. A series of experimental factors affecting enzyme catalysis including pH, temperature, substrate concentration, and enzyme activity were investigated as well as the enzyme degradation kinetics. Results showed that enzyme kinetic parameters such as Vmax and Km were obtained using the Michaelis-Menten equation with the values of 0.313 mg L−1 h−1 and 10.07 mg L−1, respectively. The optimal conditions for effective degradation of chlorpyrifos are pH of 2–6 and temperature of 20 °C with removal percentages of 62.2 %–67.3 % and 76.8 %, respectively. More than 50 % removal of chlorpyrifos was obtained with laccase activity higher than 250 U L−1. The findings suggest that laccase produced by fungi obtained from food processing residues could be a good candidate for chlorpyrifos degradation, especially under acid conditions. This study provides a new perspective on the biodegradation of organophosphate pesticides and a theoretical basis for the practical application of laccase in the remediation of soil and water polluted by chlorpyrifos.