Optimizing fermentation conditions for enhanced laccase production from Coriolus versicolor and its potential in degrading 2,4-dichlorophenol.

Abstract

As environmental pollution problems become increasingly severe, the treatment of persistent organic pollutants has emerged as a major challenge in the field of environmental protection. Laccase, as a green and efficient biocatalyst, demonstrates significant potential for application in environmental remediation due to its unique oxidation capabilities and broad substrate specificity. This study systematically investigated the optimization of conditions for laccase production by Coriolus versicolor, the impact of fed-batch feeding and co-cultivation with a second fungal strain on laccase secretion by C. versicolor, and the degradation performance of the produced laccase towards 2,4-dichlorophenol (2,4-DCP). The results showed that during submerged fermentation, the laccase activity of C. versicolor increased significantly over time, peaking on the 6th day, and then gradually declined due to nutrient depletion and metabolite accumulation. Optimization of wheat bran concentration (20 g/L) and initial pH value (5.0) facilitated laccase production. Additionally, fed-batch feeding during fermentation was beneficial for laccase secretion by C. versicolor. Co-cultivation with a filamentous fungus Penicillium significantly increased laccase production. On laccase-mediated degradation of 2,4-DCP, the optimal enzyme dosage (4.0 U/mL), substrate concentration (20 mg/L), and degradation time (60 h) were established. Addition of mediator 2, 2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (0.5 mmol/L) significantly improved degradation efficiency, achieving complete degradation of 2,4-DCP. HPLC analysis further verified the practical application of laccase in environmental remediation. This study provides technical support for the preparation of highly active laccase and its application in the remediation of organic pollutants through degradation.