Effective degradation of zearalenone by dye-decolorizing peroxidases from Pleurotus ostreatus and its metabolic pathway and toxicity analysis

Abstract

The widespread detection of zearalenone (ZEN) in cereal crops and feeds poses a significant threat to both humans and animals. Consequently, the urgency for the international community to address this issue is evident in the demand for safe and effective measures to mitigate zearalenone contamination and explore detoxification methods. In this study, a dye-decolorizing peroxidase (PoDyP4) from Pleurotus ostreatus is characterized for its impressive ZEN degradation effectiveness. PoDyP4 was demonstrated that the ability to almost completely degrade ZEN at pH 6.0 and 40 °C for 2 h, even at high concentrations of 1 mM. The promotion of enzymatic degradation of ZEN was most pronounced in the presence of Mg2+, while Cu2+ and Fe2+ exhibited a notable inhibitory effect. The degradation mechanism elucidated the detoxification of ZEN by PoDyP4 through hydroxylation and polymerization reactions. The resulting metabolic products displayed significantly reduced toxicity and minimal impact on the viability and apoptosis of mouse spermatocytes GC-2 cells, in comparison to the original ZEN. Hydrophobic contacts and hydrogen bonds were found to be crucial for ZEN-PoDyP4 stability via molecular docking. This finding suggests that PoDyP4 may have a promising application in the field of food and feed for zearalenone detoxification.