Degradation of zearalenone and aflatoxin B1 by Lac2 from Pleurotus pulmonarius in the presence of mediators
Degradation of zearalenone and aflatoxin B1 by Lac2 from Pleurotus pulmonarius in the presence of mediators
复制标题
在介体存在下，来自侧耳的 Lac2 对玉米赤霉烯酮和黄曲霉毒素 B1 的降解。
DOI：
10.1016/j.toxicon.2021.08.003
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发表时间：
2021-08-17
期刊：
影响因子：
2.8
通讯作者：
Zhao, Lihong
中科院分区：
文献类型：
--
作者：
Song, Yanyi;Wang, Yanan;Zhao, Lihong
真菌毒素污染食品和饲料已成为一个具有全球意义的问题。在真菌毒素解毒方面，漆酶生物降解已受到广泛关注。本研究将肺侧耳菌漆酶基因lac2在毕赤酵母X33酵母菌中表达，产生重组蛋白。研究了重组Lac2在ABTS、TEMPO、AS和SA四种介质存在下的酶学性质及其降解玉米赤霉烯酮（ZEN）和黄曲霉毒素B1 （AFB1）的能力。结果表明，重组Lac2的最适pH为3.5℃，最适温度为55℃。Lac2对热不敏感，在酸性和碱性条件下均稳定。在pH（4-8）和温度（40-60℃）范围内，Lac2-ABTS和Lac2-AS均能有效降解ZEN。Lac2-AS是降解AFB1效率最高的体系，在pH 7、37℃条件下，培养1h后降解率达到99.82%。最后对lac2介质氧化产物进行了结构表征。本研究为应用Lac2漆酶与AS联合降解食品和饲料中的霉菌毒素奠定了坚实的基础。
The contamination of foods and feeds with mycotoxins has been an issue of global significance. For mycotoxin detoxification, enzymatic biodegradation using laccase has received much attention. In this study, a laccase gene lac2 from the fungus Pleurotus pulmonarius was expressed in the Pichia pastoris X33 yeast strain to produce recombinant proteins. Enzymatic properties of recombinant Lac2 and its ability to degrade zearalenone (ZEN) and Aflatoxin B1 (AFB1) in the presence of four mediators (ABTS, TEMPO, AS and SA) were investigated. Result showed that the optimum pH and temperature of recombinant Lac2 were 3.5 and 55 degrees C, respectively. Lac2 was not sensitive to heat and stable under both acidic and alkaline conditions. Lac2-ABTS and Lac2-AS were efficient systems for ZEN degradation over a wide range of pH (4-8) and temperature (40-60 degrees C). Lac2-AS was the most efficient system for AFB1 degradation, reaching 99.82% of degradation at pH 7 and 37 degrees C after 1 h of incubation. Finally, the Lac2-mediator oxidation products were structurally characterized. This study lays a solid foundation for the application of Lac2 laccase combined with AS for degrading mycotoxin in food and feed.