State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
Toxins (Basel). 2021 Jun 19;13(6):429. doi: 10.3390/toxins13060429.
The co-occurrence of multiple mycotoxins, including aflatoxin B (AFB), zearalenone (ZEN) and deoxynivalenol (DON), widely exists in cereal-based animal feed and food. At present, most reported mycotoxins degrading enzymes target only a certain type of mycotoxins. Therefore, it is of great significance for mining enzymes involved in the simultaneous degradation of different types of mycotoxins. In this study, a dye-decolorizing peroxidase-encoding gene from SCK6 was cloned and expressed in BL21/pG-Tf2. The purified recombinant DyP was capable of oxidizing various substrates, including lignin phenolic model compounds 2,6-dimethylphenol and guaiacol, the substrate 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid), anthraquinone dye reactive blue 19 and azo dye reactive black 5, as well as Mn. In addition, DyP could efficiently degrade different types of mycotoxins, including AFB, ZEN and DON, in presence of Mn. More important, the toxicities of their corresponding enzymatic degradation products AFB-diol, 15-OH-ZEN and CHO were significantly lower than AFB, ZEN and DON. In summary, these results proved that DyP was a promising candidate for the simultaneous degradation of multiple mycotoxins in animal feed and food.
多种真菌毒素(包括黄曲霉毒素 B1(AFB1)、玉米赤霉烯酮(ZEN)和脱氧雪腐镰刀菌烯醇(DON))在谷物型动物饲料和食品中广泛存在。目前,大多数报道的真菌毒素降解酶仅针对特定类型的真菌毒素。因此,挖掘同时降解不同类型真菌毒素的酶具有重要意义。本研究从 SCK6 中克隆并在 BL21/pG-Tf2 中表达了一种染料脱色过氧化物酶编码基因。纯化的重组 DyP 能够氧化各种底物,包括木质素酚模型化合物 2,6-二甲基苯酚和愈创木酚、底物 2,2'-偶氮双(3-乙基苯并噻唑啉-6-磺酸)、蒽醌染料活性蓝 19 和偶氮染料活性黑 5 以及 Mn。此外,DyP 能够在 Mn 的存在下有效降解不同类型的真菌毒素,包括 AFB1、ZEN 和 DON。更重要的是,它们相应酶解产物 AFB1-二醇、15-OH-ZEN 和 CHO 的毒性明显低于 AFB1、ZEN 和 DON。总之,这些结果证明 DyP 是一种很有前途的候选酶,可用于同时降解动物饲料和食品中的多种真菌毒素。