【摘要】 糖化酵母结构基因ＳＴＡ编码分泌到胞外的葡萄糖淀粉酶（α－１，４－葡聚糖－葡糖水解酶，ＥＣ３．２．１．３），俗称糖化酶。通过限制性内切酶Ｓａｕ３Ａ部分酶切糖化酵母染色体，以穿梭质粒ＹＥＰ１３作载体，建立糖化酵母的基因文库，转化ｓｔａ°ｉｎｈ°型酿酒酵母受体菌Ｃ＿２，筛选出三株ｓｔａ￣＋转化子，检测出５．３ｋｂ大小的外源基因片段，继而采用薄层层析、ＫＮＲ染料测酶活性等方法对外源基因产物进行了鉴定并测定了酶活最佳反应条件。更多还原

【Abstract】 The Saccharomyces diastaticus structural gene STA, encoding an extracellular glucoamylase has been cloned. A genomic library of S. diastaticus was constructed in the yeast──E.coli shuttle vector YEP13. Recombinant plasmids from the library were used to transform S. cerevisiae C2 (sta°inh°) to select sta+clone. Three transformants with foreign fragment larger than 5kb were obtained and the product of the foreign fragment was analysised with chromatography and KNR enzyme assay. The optimum condition of enzyme activity was also tested.更多还原