大肠杆菌BL21(DE3)生产β-环状糊精转移酶发酵条件的优化

采用正交试验确定大肠杆菌BL21 (DE3)产β-环糊精转移酶的发酵条件.结果表明,生产β-环状糊精转移酶的最适条件为:接种量1％,100mL三角瓶装液量15mL,初始pH值为7.0,Ca2+浓度为1.25mmol/L,Mg2+浓度为2.50mmol/L,温度控制在37℃,转速控制为150r/min.当OD600达到1.4时,加入终浓度5.0g/L的α-乳糖,转速提高至170r/min,37℃诱导12h后过滤,β-CGTase酶活最高可达16.3μ/mL.

Optimization of the culture conditions of E.coli BL21 (DE3)producing β-cyclodextrin glucanotransferase

The culture condition for producing β-cyclodextrin glucanotransferase by E.coli BL21(DE3) was primarily established by orthogonal experimental design. The results showed that the optimal fermentation conditions were as follows: the inoculum size was 1%; The load of 100ml-flask was 15ml; initial pH value was 7.0; the concentration of Ca2+ was 1.25mmol/L, the concentration of Mg2+ was 2.50mmol/L, incubation temperature was 37℃ and the speed was 150r/min. When the value of OD600 reached 1.4, α-lactose was added so as to the final concentration to 5.0g/L, the speed was increased to 170r/min, and induced 12h at 37℃ then filtered, the β-CGTase activity reached the maximum value as 16.3μ/ml. Key words: