在酿酒酵母中共表达XYLA和XKS1基因后利用木糖的初步研究  

Construction of Saccharomyces cerevisiae expressing XYLA and XKS1 and study on the effect of the xylose utilization

作　　者：李永建[1] 严明[1] 丁莉[1] 许伟[1] 许琳[1] yh 

机构地区：[1]南京工业大学制药与生命科学学院,南京210009

出　　处：《生物加工过程》2006年第4期65-69,共5页Chinese Journal of Bioprocess Engineering

基　　金：国家973项目(2003CB716000);国家自然科学重点基金项目(20336010)

摘　　要：为了使酿酒酵母较好地利用木糖产生乙醇,将来自Thermus thermophilus的木糖异构酶基因XYLA和酿酒酵母自身的木酮糖激酶基因XKS1,构建到酵母表达载体pESC-LEU中,导入酿酒酵母YPH499中,同时成功表达了两种酶基因。该菌以木糖为唯一碳源进行限氧发酵,木糖的利用率为9.64%,为宿主菌的4.17倍,产生2.22 mmol.L-1的乙醇。同时初步探讨了两种酶基因的表达量对酿酒酵母发酵木糖生成乙醇的影响。木糖异构酶对木糖的利用起关键性的作用,木酮糖激酶的过量表达不利于乙醇生成。In order to construct a strain of Saccharomyces cerevisiae that can utilize the xylose to produce ethanol, the XYL4 gene from Thermus thermophilus, encoding xylose isomerase （XI）, and XKS 1 gene from S. cerevisiae were integrated into the plasmid of pESC-LEU. The two genes were expressed in the recombinant Saccharomyces cerevisiae strain YPH499.The recombinant strain fermented xylose under oxygen-limited condition. The result showed that 9.64% of xylose was consumed,4.17 times higher than the parent strain. 2.22 mmol·L^-1 ethanol was produced. At the same time, the explaination on the effect of the XI and XK to xylose utilization were given. It showed that xylose isomerase was important in utilizing xylose, but xylulokinase overexpressed was not in favor of getting more ethanol.

关 键 词：木糖异构酶 木酮糖激酶 木糖 酿酒酵母 乙醇 

分 类 号：Q786[生物学—分子生物学]