Biodegradation based on microbial enzymes is considered to be one of the promising ways for controlling patulin contamination. However, few patulin degrading enzymes have been isolated and characterized until now. Here, a short-chain dehydrogenase/reductase (SDR) gene, CgSDR, was cloned from a yeast strain Candida guilliermondii, and expressed in Escherichia coli. The expression of CgSDR conferred a strong patulin tolerance and degradation ability to E. coli, and purified CgSDR could transform patulin into E-ascladiol in vitro with NADPH as a coenzyme. Moreover, addition of CgSDR at 150 μg/mL could reduce 80% of patulin in apple juice and the biodegradation process did not affect the quality of the apple juice. A molecular docking analysis and site-directed mutagenesis indicated that CgSDR might interact with patulin via VAL188 as an active binding sites. The findings provide new insights for developing enzymic formulations for mycotoxin detoxification in fruit derived products.

基于微生物酶的生物降解被认为是控制棒曲霉素污染的有前途的方法之一。然而，到目前为止，分离并鉴定了很少的棒曲霉素降解酶。在这里，短链脱氢酶/还原酶（SDR）基因CgSDR是从酵母菌株念珠菌念珠菌（Candida guilliermondii）中克隆的，并在大肠杆菌中表达。的表达CgSDR赋予强烈的棒曲霉素耐受性和降解的能力的大肠杆菌，并纯化CgSDR可以改变成棒曲霉素E-ascladiol体外以NADPH作为辅酶。此外，添加150μg/ mL的CgSDR可以减少苹果汁中80％的棒曲霉素，并且生物降解过程不会影响苹果汁的质量。分子对接分析和定点诱变表明，CgSDR可能通过VAL188作为有效的结合位点与巡视蛋白相互作用。该发现为开发水果衍生产品中霉菌毒素解毒酶制剂提供了新的见识。