Xing Mengyang, Chen Yong, Li Boqiang, Tian Shiping
Key Laboratory of Plant Resources, Institute of Botany, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Key Laboratory of Plant Resources, Institute of Botany, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing 100093, China.
Food Chem. 2021 Jun 30;348:129046. doi: 10.1016/j.foodchem.2021.129046. Epub 2021 Jan 11.
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展青霉素污染的一种有前景的方法。然而，到目前为止，很少有展青霉素降解酶被分离和鉴定。在此，从季也蒙毕赤酵母菌株中克隆了一个短链脱氢酶/还原酶（SDR）基因CgSDR，并在大肠杆菌中表达。CgSDR的表达赋予了大肠杆菌强大的展青霉素耐受性和降解能力，纯化的CgSDR可以以NADPH作为辅酶在体外将展青霉素转化为E-阿斯克拉二醇。此外，以150μg/mL添加CgSDR可以降低苹果汁中80%的展青霉素，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作为活性结合位点与展青霉素相互作用。这些发现为开发用于水果衍生产品中霉菌毒素解毒的酶制剂提供了新的见解。
