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Thermusthermophilus的木糖异构酶(XI)基因xylA和酿酒酵母(Saccharomycescerevisiae)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-27,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。
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.
出处
《中国生物工程杂志》
CAS
CSCD
北大核心
2005年第9期69-73,共5页
China Biotechnology
基金
国家自然科学基金委员会与中国节能投资公司联合研究基金资助项目(50273019)
国家重点基础研究发展计划资助项目(2003BC716006
2004CB719702)
