玉米赤霉烯酮降解酶ZHD795编码基因克隆及降解活性研究

玉米赤霉烯酮(zearalenone, ZEN)是主要由镰刀菌属产生的一类极易污染粮食作物的真菌毒素。利用生物酶的专一性破坏ZEN的分子结构是消除ZEN污染的有效手段。筛选得到一株可以高效降解ZEN的微生物菌株,通过基因组测序得到了该菌株的全基因组序列信息。以ZEN降解酶ZHD101序列为模板与测得的全基因进行序列比对,得到了同源序列ZHD795。在体外重组表达ZHD795蛋白,经亲和色谱纯化后对ZEN分子进行降解活性实验,HPLC结果表明,ZHD795蛋白可以降解ZEN分子；同时比较了ZHD795与ZHD101对ZEN的降解活性,在相同条件下ZHD795对ZEN的降解活性是ZHD101的2.5倍,从而获得了一个具有良好应用前景的高活性ZEN降解酶。

Cloning of ZEN-Degrading Enzyme ZHD795 and Study on Degradation Activity

Zearalenone (ZEN) is a kind of fungal toxin produced mainly produced by Fusarium, which can easily contaminate food crops. Using the specificity of biological enzyme to destroy the molecular structure of ZEN is an effective method to eliminate ZEN pollution. Through screening, we found a microbial strain that can efficiently degrade ZEN, and the whole genome sequence information of the strain was obtained by the genome sequencing. The sequence alignment of ZEN-degrading enzyme ZHD101 was then performed, and the homologous sequence ZHD795 was obtained. To determine its ZEN-degrading activity, the gene fragment was synthesized chemically and cloned into the E.coli expression system, and the protein was then purified using affinity chromatography. The degradation activity was tested and the HPLC results showed that ZHD795 could degrade ZEN molecule efficiently. At the same time, the level of ZEN degradation activity of ZHD795 and ZHD101 was compared. Under the same conditions, the degradation activity of ZHD795 to ZEN was 2.5 times than that of ZHD101. This research showed that a highly active ZEN degradation enzyme with good application prospect was obtained.