西藏罗伦隐球酵母对玉米赤霉烯酮的生物降解机制研究

玉米赤霉烯酮（ZEN）作为污染粮食的主要真菌毒素，具有生殖发育、细胞及遗传毒性。生物清除法高效专一，是目前处理ZEN污染粮食的重要绿色方法，但清除效果易受环境影响，稳定性较差限制了其广泛应用。前期研究结果表明，西藏罗伦隐球酵母对ZEN具有较好的降解效果和环境胁迫耐受特性。为阐明其降解机理，本项目将通过转录组学方法、转基因技术并结合色谱层析方法与MALDI-TOF-MS纯化并鉴定该酵母降解ZEN的关键酶；同时利用LC-MS/MS、小鼠睾丸间质细胞活性与凋亡评价实验、de novo转录组和iTRAQ蛋白组技术，以及RT-qPCR和Western blot，研究酵母在不同环境胁迫条件下对ZEN的降解效果、产物变化规律和响应机制，全面解析西藏罗伦隐球酵母降解ZEN的作用机理，为克服生物脱毒稳定性差的瓶颈问题提供新的解决方法和理论依据。

As one of the main mycotoxins in cereal contamination, zearalenone has the properties of reproductive and developmental toxicity, cytotoxicity and genetic toxicity. The biological elimination is an important method of zearalenone green detoxification, because of its high efficiency and specificity without damage to grain. However, its detoxification effect is easily affected by the environmental conditions, and this poor stability is the main problem limiting its application. On account of the unique regional environment, the yeasts from Tibet have a potential to overcome this problem. The preliminary screening work shows that Cryptococcus laurentii from Tibet not only has a good biodegradation effect to ZEN, but also has a strong stability and stress tolerance. To elucidate its degradation mechanism, the project will purify and identify the key biodegradation enzymes through RNAseq, transgenic technology, chromatographic method and MALDI-TOF-MS; meanwhile, the variation of biodegradation effect, products and responding mechanism will also be studied by LC-MS/MS, TM3 cell activity and apoptosis test, de novo RNAseq, iTRAQ proteomics, RT-qPCR and Western blot. The comprehensive analysis of the biodegradation characteristics and mechanism of Tibetan C. laurentii to ZEN will provide a new method and theoretical basis for overcoming the poor stability of biological detoxification.