真菌毒素玉米赤霉烯酮生物降解的研究进展

Progress in bio-degradation of mycotoxin zearalenone

摘要:

玉米赤霉烯酮 (Zearalenone，ZEN) 及衍生物是一类主要由镰刀菌属的真菌产生的非甾体雌激素类真菌毒素，广泛存在于玉米、大麦、小麦和高粱等谷物饲料及其副产品中，严重危害牲畜及人类健康，迫切需要相关的技术对ZEN进行降解脱毒。传统的物理化学方法不能有效去除谷物中的毒素，并会破坏谷物的营养成分，影响食物口感，甚至造成二次污染，因此利用生物工程技术对ZEN及其衍生物进行脱毒是未来解决这一问题的主要方法。本文简要介绍了ZEN及衍生物和降解ZEN的微生物种类、降解特性，然后详细介绍了目前研究的ZEN降解酶种类、解析唯一的蛋白结构及其异源表达和应用情况，以期为通过分子酶工程和发酵工程等生物工程技术降低ZEN降解酶的成本提供指导，从而提高食品安全。

Abstract:

Zearalenone (ZEN) and its derivatives are non-steroidal estrogenic mycotoxins mainly produced by Fusarium species. They are widely distributed in grain feeds originated from maize, barley, wheat and sorghum, causing serious harm to animal and human health. Currently, there is a pressing need of an efficient technology for ZEN degradation and detoxification. Because traditional physical and chemical methods could not effectively detoxify ZEN in grains, and might also affect the grain nutrients and food taste, and even result in secondary pollution, the biological technologies are developed to detoxify ZEN and its derivatives. In this paper, we reviewed the structure of ZEN and its derivatives, the fungi and bacteria species with ability of degradation of ZEN. In addition, the characterization, protein sequences and conformation of currently identified ZEN degrading enzymes, the only solved ZHD structure from Clonostachys rose were analyzed and compared, and the enzymes heterologous expression and application were also reviewed. This review will provide reference for reducing the cost of ZEN degrading enzymes by biological technologies such as enzyme engineering and fermentation engineering.