【摘要】 木糖还原酶是酵母代谢木糖发酵的关键酶之一。根据已报道的木糖还原酶基因的全序列设计引物,从休哈塔假丝酵母中克隆得到1 110 bp大小的片段。将木糖还原酶基因亚克隆到酿酒酵母的整合表达载体p406ADH1中,醋酸锂转化法将线性化重组质粒p YX-AK-xyl1转化到酿酒酵母W5,对阳性转化子进行酶活测定,结果表明,以辅酶DANH和NADPH为底物诱导,转化子均表现出活性,酶活分别为6.513 U/mg和7.080 U/mg,是受体菌W5酶活的1.4倍(NADH)和1.3倍(NADPH),其酶活比为0.919。更多还原

【Abstract】 Xylose reductase is the key enzyme in the yeast metabolic xylose fermentation. One fragment was cloned from genomic DNA of Candida shehatae through PCR with prime designed according to the reported sequences. Then was subcloned into the Saccharomyces cerevisiae integration expression vector. The linear recombinant plasmid p YX-AK-xyl1 was transformed into Saccharomyces cerevisiae W5 by Lithium acetate transformation, transformants were carried out on the determination of enzyme activity showed that the different coenzyme(NADH and NADPH) as substrate induction,were show activity were 6.513 U/mg and 7.080 U/mg, than the receptor strain W5 to increase by 1.4 times and 1.3times, but the activity less than original strain 20335, the activity ratio were 0.919.更多还原