Identification and rational engineering of a novel zearalenone-degrading enzyme from Fonsecaea erecta

Zearalenone (ZEN) is a secondary metabolite produced by Fusarium species that threatens food safety and animal health. In this study, we identified and isolated a novel ZEN-degrading enzyme FeZ12 from Fonsecaea erecta through sequence homology alignment, systematic learning models (SoluProt, DeepSoluE), and molecular dynamics (MD) simulations. FeZ12 was successfully heterologously expressed in Escherichia coli and exhibited optimal activity at 37 °C and pH 7.0. To enhance enzyme activity and thermal stability, multiple FeZ12 mutants were constructed based on structure-guided and mutation prediction analyses. Single mutants G179R, P127V, and T9V exhibited 2.8-fold, 2.5-fold, and 2.2-fold higher activities than the wild type, respectively. The triple mutant T9V/P127V/G179R exhibited a 3.2-fold activity increase and markedly improved thermal stability, retaining 65% of its activity after incubation at 45 °C for 30 min. MD simulations revealed that mutations stabilized the FeZ12 structure and optimized the catalytic geometry. This work provides a practical engineering route and a thermostable enzyme candidate for ZEN detoxification in food and feed systems, with potential for industrial application.