[Condition optimization for degradation of chlorophenols using laccase from Amillariella mellea]

Crude laccase extracted from the Amillariella mellea fermentation broth was directly used to catalyze the degradation of 2,4-chlorophenol (2,4-DCP) and 2-chlorophenol (2-CP). The effects of reaction time, pH, temperature, chlorophenol concentration, and laccase dosage on the removal efficiency of chlorophenols were investigated. Optimal catalytic conditions for the degradation of chlorophenols were obtained and the degradation kinetics were analyzed. The results indicated that the crude laccase from Amillariella mellea was able to effectively degrade 2,4-DCP and 2-CP, with higher catalytic ability towards 2,4-DCP degradation. For 2,4-DCP degradation, the optimal temperature was 40 degrees C, the optimal substrate concentration was 75 mg x L(-1), the optimal enzyme dosage was 0. 1 U x mL(-1), and the optimal pH was 6.5. Under these conditions, the maximum degradation rate of 2,4-DCP reached > 97% after 10 h. For 2-DCP degradation, the optimal temperature was 50 degrees C, the optimal substrate concentration was 100 mg x L(-1), the optimal enzyme dosage was 0.1 U x mL(-1), and the optimal pH was 6. Under these conditions, the maximum degradation rate of 2-CP was over 93% after 10 h. The reaction process of laccase-catalyzed 2,4-DCP and 2-CP degradation obeyed the first-order kinetics equation. The laccase from Amillariella mellea was able to effectively degrade chlorophenols, indicating its potential application value in phenolic pollutant control and environmental protection.