马克斯克鲁维酵母中葡萄糖对木糖醇脱氢酶基因表达的关键转录抑制因子的研究

高效利用木质纤维素生物质水解产物中的葡萄糖和木糖是提高生物基化学品生产的经济性的重要基础。耐热的马克斯克鲁维酵母具有酿酒酵母所不具有的高效利用木糖的能力，但是葡萄糖效应会降低其对木糖的利用效率。本项目前期研究发现马克斯克鲁维酵母中葡萄糖对木糖利用的抑制在Snf1下游是新的信号路径，并确定木糖醇脱氢酶基因是木糖利用路径中受严谨调控的关键基因。我们以此基因表达的转录抑制因子为研究对象，采用木糖醇脱氢酶启动子区DNA的DNA pulldown和酵母单杂交技术直接筛选，CoIP-MS、磷酸化蛋白组学分析等技术辅助筛选来获得候选的转录抑制因子，通过基因敲除、突变体构建、RNA-seq、ChIP-seq等技术鉴定和研究该转录抑制因子的调控机制。本项目将明确马克斯克鲁维酵母中葡萄糖对木糖醇脱氢酶基因表达的抑制机理，研究成果不仅可以促进葡萄糖和木糖高效共利用菌株的构建，对绿色生物制造也有实际应用价值。

High efficient utilization of the glucose and xylose in lignocellulosic biomass hydrolysate is of great importance in chemical production from these renewable sources. Thermo-tolerant Kluyveromyces marxianus can efficiently utilize xylose which Saccharomyces cerevisiae cannot. However, the glucose effect reduces the xylose consumption ability of K. marxianus with the presence of glucose. The results of our previous study indicated that the pathway of glucose repression to xylose utilization at the downstream of Snf1 is a new pathway. In this project, we will focus on the key transcription repressor to the xylitol dehydrogenase gene expression. This transcription repressor will be screened by DNA pulldown, yeast one hybrid directly with the DNA fragments from the promoter of xylitol dehydrogenase gene. The complementary strategy through CoIP and phosphoproteomics will also be conducted. Then, gene deletion and mutants construction combined with RNA-seq, ChIP-seq will be used to confirm the function of obtained transcription repressor and analyze its regulation mechanism. In this project, the key transcription repressor of glucose to xylitol dehydrogenase gene expression and its mechanism will be unriddled. The results of this project will not only enhance the glucose and xylose co-utilization K. marxianus strain construction, but also make great contribution to the green manufacture.