基因工程技术在黄曲霉毒素生物降解中的应用

发布时间：2018-07-29 10:06

【摘要】：黄曲霉毒素具有强致癌性、致突变性和致畸性,影响动物生产性能,降低饲料转化效率,减少产肉量、产蛋量和产奶量,增加动物发病率和死亡率,给畜牧业造成巨大的经济损失。另外,黄曲霉毒素通过肉、蛋、奶食物链传递给人类,严重威胁人类健康。因此,黄曲霉毒素的防控已经成为全球性高度关注的问题。目前,饲料中黄曲霉毒素的脱毒方法主要采用物理吸附,如蒙脱石、活性炭、酵母细胞壁等,但物理吸附仅是吸附了黄曲霉毒素,并不能减少毒素的量,最终饲料中被吸附的毒素在体内解吸附后排出体外,可造成环境的二次污染。另外吸附剂效果不稳定,可能会吸附饲料中的维生素等营养物质,造成饲料品质下降。其中,生物降解法具有解毒彻底、专一性强,不影响饲料的营养价值且能够避免毒素的重新产生等优点,从而备受研究者的关注。目前,有越来越多的研究报道了真菌、细菌及其代谢产生的酶能够降解黄曲霉毒素,而鲜有关于降解黄曲霉毒素重组酶的报道。基因工程技术在黄曲霉毒素生物降解中的运用,可采用现代分子生物学的方法,从复合解毒酶中分离纯化出特定的蛋白。但因微生物降解酶分离纯化过程复杂、酶活不稳定、酶作用条件苛刻,较难用于实际生产。因此,人们利用基因工程手段将活性高的解毒酶基因进行基因克隆,实现降解酶基因在原核或真核工程菌种的异源高效表达,为酶制剂在降解霉菌毒素的实际生产中作用研究奠定了理论基础。文章就基因工程技术在黄曲霉毒素降解中的运用研究进展及未来发展方向进行综述,为饲料和食品中霉菌毒素生物降解酶的运用提供理论基础和实践依据。
[Abstract]:Aflatoxin has strong carcinogenicity, mutagenicity and teratogenicity, which affects animal productivity, reduces feed conversion efficiency, reduces meat production, egg production and milk production, and increases animal morbidity and mortality. Great economic losses have been caused to animal husbandry. In addition, aflatoxins are transmitted to humans through the meat, eggs, and milk food chains, posing a serious threat to human health. Therefore, the prevention and control of aflatoxin has become a global concern. At present, the main detoxification methods of aflatoxin in feed are physical adsorption, such as montmorillonite, activated carbon, yeast cell wall, etc. The toxin adsorbed in the final feed is desorbed in vivo and discharged from the body, which can cause the secondary pollution of the environment. In addition, the effect of adsorbent is unstable, it may absorb vitamins and other nutrients in feed, resulting in the decline of feed quality. Among them, biodegradation method has the advantages of thorough detoxification, strong specificity, does not affect the nutritional value of feed and can avoid the recurrence of toxins, so it has attracted the attention of researchers. At present, more and more studies have reported that fungi, bacteria and enzymes produced by their metabolism can degrade aflatoxin, but there are few reports on the degradation of aflatoxin recombinant enzymes. The application of genetic engineering in the biodegradation of aflatoxin can be used to isolate and purify specific proteins from compound detoxification enzymes by modern molecular biology. However, it is difficult to be used in practical production because of the complex process of microbial degradation enzyme separation and purification, the instability of enzyme activity and the harsh conditions of enzyme action. Therefore, the highly active detoxifying enzyme gene was cloned by genetic engineering, and the degradation enzyme gene was expressed in prokaryotic or eukaryotic engineering strains. It lays a theoretical foundation for the study of the role of enzyme in the production of mycotoxin degradation. In this paper, the application of genetic engineering technology in the degradation of aflatoxin is reviewed, which provides a theoretical and practical basis for the application of mycotoxin biodegradable enzymes in feed and food.
【作者单位】：中国农业大学动物科技学院/动物营养学国家重点实验室;山西大学生命科学学院;
【基金】：国家公益性行业(农业)科学专项(201403047) 大北农青年学者研究计划动物营养学国家重点实验室项目
【分类号】：Q789;S859.8

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