中文摘要：

根据代谢工程原理，采取多拷贝整合策略，利用整合载体pYMIKP，将来自嗜热细菌Thermus thermophilus的木糖异构酶（Ⅺ）基因xylA和酿酒酵母（Saccharomyces cerevisiae）自身的木酮糖激酶（XK）基因XKS1，插入酿酒酵母工业菌株NAN-27的染色体中，得到工程菌株NAN-114。酶活测定结果显示，NAN-114中Ⅺ和XK的活性均高于出发菌株NAN-7，表明外源蛋白在酿酒酵母工业菌株中得到活性表达。对木糖、葡萄糖共发酵摇瓶实验结果表明，工程菌NAN-114消耗木糖4．6g／L，产生乙醇6．9g／L，较出发菌株分别提高了43．8％和9．5％。首次在酿酒酵母工业菌株中建立了Ⅺ路径的木糖代谢途径。

英文摘要：

In order to develop an industrial strain of Saccharomyces cerevisiae that can utilize the xylose to produce ethanol, an integrating plasmid pYMIK-xy114 containing the xylA gene from Thermus thermophilus, encoding xylose isomerase （Ⅺ）, and XKS1 gene from S. cerevisiae, encoding xylulokinase （XK） was constructed. The integrating plasmid pYMIK-xy114 was transformed into a S. cerevisiae industrial strain NAN-27 producing the recombinant strain NAN-114. Upon transformation, multiple copies of the xylose-utilizing genes were integrated into the genome rDNA locus of S. cerevisiae. The results of enzymes assays showed that the Ⅺ and XK activity of NAN-114 was higher than that of parent strain. The resulting recombinant strain could coferment glucose and xylose to ethanol under oxygen-limited condition. The NAN-114 consumed 4.6g/L xylose and produced 6.9g/L ethanol, which were 43.8% and 9.5% higher than the parent strain NAN-27 respectively.