Biodegradation mechanisms and detoxification profiles of zearalenone by Clonostachys and Gliocladium biocontrol strains

Zearalenone (ZEA) frequently contaminates cereals and poses risks to human and animal health, highlighting the need for effective detoxification approaches. In this study, the biocontrol agents Clonostachys rosea, Gliocladium penicillioides, and G. catenulatum were shown to tolerate 50 μg/mL ZEA, while G. deliquescens and G. viride showed sensitivity to 10 μg/mL ZEA. The tolerant strains exhibited comprehensive degradation capacity against ZEA and its toxic derivatives (α/β-zearalanol and α/β-zearalenol), transforming 20 μg/mL ZEA within 48 h. Notably, C. rosea showed the highest degradation capacity, not only transforming ZEA faster but also degrading over 95.5 % of 50 μg/mL α/β-zearalanol and α-zearalenol, along with 36.2-54.4 % β-zearalenol within 72 h. Additionally, the mRNA levels of zhdr52 and zhdp83 were significantly upregulated during the biotransformation process, suggesting their involvement in this process. ZEA degradation products were identified as hydrolyzed ZEA (H-ZEA) and decarboxylated hydrolyzed ZEA (D-ZEA) by LC-MS analysis. Importantly, the degradation products H-ZEA and D-ZEA showed markedly reduced cytotoxicity compared to ZEA, as evidenced by the absence of significant cytotoxic effects on normal human hepatocytes and renal cells in CCK-8 assays. This study clarifies the ZEA biodegradation mechanisms of C. rosea, G. penicillioides, and G. catenulatum, identifying three promising fungal candidates for ZEA biocontrol and advancing the development of ZEA detoxification strategies.