高温发酵在生产中有很多优势，而葡萄糖与木糖共发酵是提高木质纤维素乙醇生产效益的基础。马克思克鲁维酵母具有在高温(≥42℃)下快速生长和较好的发酵能力，并且天然能利用木糖。目前该酵母已实现对葡萄糖/木糖的共发酵，但葡萄糖对木糖利用抑制的现象极大影响了糖醇转化率。本项目拟从糖转运和葡萄糖感应系统两个关键节点探寻引起葡萄糖抑制的关键蛋白。①在无己糖转运蛋白的酵母菌株中，评价内源性主要己糖转运蛋白的糖转运能力，分析葡萄糖对木糖转运抑制的动力学特性，结合己糖转运蛋白基因选择性敲除和木糖特异性糖转运蛋白基因重组表达以构建葡萄糖和木糖均衡转运的糖转运体系；②通过基因的预测和敲除确定感应葡萄糖并抑制木糖利用的关键蛋白，通过基因工程改造减弱葡萄糖抑制效应；③结合构建的糖转运体系，构建高温下能同时高效利用葡萄糖和木糖的马克思克鲁维酵母平台菌株，为构建高效利用木质纤维素生物质生产化学品的耐高温酵母菌株奠定基础。

Fermentation at elevated temperature has lots of advantages in bioconversion, and co-fermenation of glucose and xylose is very important to economically industrial procedure. Kluyveromyces marxianus can grow fast and ferment very well at elevated temperature (≥42℃). Though the engineered K. marxianus could use glucose and xylose simultaneously, the xylose assimilation ability can be repressed by glucose and thereafter, the yield of products decreased. In this study, the key proteins in the repression procedure will be clarified through hexose transporters and glucose sensing system. Firstly, the main hexose transporters will be cloned and recombinantly expressed in null hexose transporter yeast strain, and the kinetic properties of xylose and glucose transportation will be investigated to determine the function of each transporter in K. marxianus. A balanced hexose transporter combination which can transport glucose and xylose simultaneously will be constructed. Secondly, the genes of key proteins in glucose senesing and repression system will be determined through gene disruption, and genetic modification will be conducted to reduce or eliminate the glucose repression in K. marxianus. Finally, the glucose repression elimination and balanced hexose transporter system are combined to construct a thermo-tolerant glucose and xylose simultaneously assimilating yeast platform. It should be a very useful foundation for high-efficient lignocellulosic biomass assimilating and chemical producing thermo-tolerant yeast construction.