中文摘要：

为实现来源于Paenibacillus macerans JFB05-01的α-环糊精葡萄糖基转移酶（α-CGT酶）的高效胞外表达,以含分泌型信号肽OmpA的大肠杆菌E.coliBL21（DE3）{pET-20b（＋）/α-cgt}为研究对象,比较了其在不同诱导条件下复合与合成培养基中生长产酶的规律。结果表明在添加甘氨酸的条件下采用合成培养基,以0.8g/L/h的乳糖进行流加诱导所得的胞外酶活和生产强度最高。在该条件下发酵30小时后胞外α-CGT酶的环化活性达113.0U/ml（水解活性为79100.0IU/ml）,是复合培养基胞外产酶的2.3倍,完全满足工业化生产的需求。

英文摘要：

In order to achieve efficient extracellular production of α-cyclodextrin glycosyltransferase （α-CGTase）,E.coli BL21 （DE3） carrying the α-cgt gene of Paenibacillus macerans JFB05-01 was investivated.By comparison of different induction conditions in complex and synthetic medium,the highest extracellular α-CGTase activity reached 113.0 U/ml （hydrolysis activity was 79 100.0 IU/ml）at 30 h of culture in synthetic medium.The optimized condition is as follows：fed 0.8 g/L/h lactose as inducer in synthetic medium,which contains glycine.The enzyme production from this condition was as 2.3 times as that in complex medium.