Simultaneous degradation of aflatoxin B1, zearalenone, and deoxynivalenol by Trametes versicolor laccases

Background Multi-mycotoxin co-contamination in staple grains poses a major challenge to food quality and safety, underscoring the urgent need for detoxification approaches capable of simultaneously degrading multiple mycotoxins. This study investigates the potential of Trametes versicolor laccase as a biocatalyst for the simultaneous degradation of aflatoxin B 1 (AFB 1 ), zearalenone (ZEN), and deoxynivalenol (DON). Methods Single-factor experiments and response surface methodology were used to optimize fermentation conditions for T. versicolor strain Tv-1 under submerged fermentation to produce laccase. The secreted laccase was purified using ammonium sulfate fractionation, dialysis, and anion exchange chromatography. Enzymatic properties, including optimal temperature, pH, thermal stability, and pH stability, were analyzed to determine suitable conditions for mycotoxin degradation. Results Laccase activity in the fermentation broth reached a maximum of 6843.14 U/L after 7.9 days at 28°C, with an initial medium pH of 5.4 and a medium volume of 105 mL. T. versicolor laccase exhibited maximum activity at 50°C and pH 4.5, but for practical detoxification purposes, 30°C and pH 4.5 were selected based on both stability and enzymatic activity considerations. Using laccase preparation S3, simultaneous degradation of AFB 1 , ZEN, and DON was achieved under mediator-free conditions, with degradation rates of 32.88, 91.88, and 54.45%, respectively. Conclusion These findings demonstrate that T. versicolor laccase can serve as a mediator-free and environmentally friendly biocatalyst for the simultaneous degradation of AFB 1 , ZEN, and DON. However, degradation efficiency decreased at higher initial mycotoxin concentrations and under multi-mycotoxin coexistence conditions, indicating that further optimization is still required for practical applications.