Ji_2022_Foods_11_

Zearalenone (ZEN) and its derivatives pose a serious threat to global food quality and animal health. The use of enzymes to degrade mycotoxins has become a popular method to counter this threat. In this study, Aspergillus niger ZEN-S-FS10 extracellular enzyme solution with ZEN-degrading effect was separated and purified to prepare the biological enzyme, FSZ, that can degrade ZEN. The degradation rate of FSZ to ZEN was 7580% (pH = 7.0, 28 degreesC). FSZ can function in a temperature range of 2838 degreesC and pH range of 2.07.0 and can also degrade ZEN derivatives (alpha-ZAL, beta-ZOL, and ZAN). According to the enzyme kinetics fitting, ZEN has a high degradation rate. FSZ can degrade ZEN in real samples of corn flour. FSZ can be obtained stably and repeatedly from the original strain. One ZEN degradation product was isolated: FSZP(C18H26O4), with a relative molecular weight of 306.18 g/mol. Amino-acid-sequencing analysis revealed that FSZ is a novel enzyme (homology < 10%). According to the results of molecular docking, ZEN and ZAN can utilize their end-terminal carbonyl groups to bind FSZ residues PHE307, THR55, and GLU129 for a high-degradation rate. However, alpha-ZAL and beta-ZOL instead contain hydroxyl groups that would prevent binding to GLU129; thus, the degradation rate is low for these derivatives.