产L-5-甲基四氢叶酸工程菌自动诱导培养基的优化

考察了自动诱导培养基代替异丙基-β-D-巯基半乳糖苷(IPTG)培养基诱导四氢叶酸还原酶在重组大肠杆菌BL21(DE3)中表达的可行性,对自动诱导培养基自诱导时的乳糖浓度和葡萄糖添加量进行优化,并与IPTG诱导培养基进行比较,确定了自动诱导培养基配方:葡萄糖1.8 mmol/L、乳糖3 mmol/L、胰蛋白胨10 g/L、酵母膏5g/L、NaCl 10 g/L。HPLC结果显示,自诱导与IPTG诱导条件下的L-5-甲基四氢叶酸产量接近。

Auto-induction Medium Optimization of Engineering Bacteria Producing L-5-Methyltetrahydrofolic Acid

The feasibility of expression of tetrahydrofolic acid reductase in recombinant E.coli BL21(DE3) induced by auto-induction medium instead of IPTG was investigated.The factors affecting the induction of target gene expression such as the lactose concentration and the amount of glucose were determined.The composition of the optimal induction medium was determined as follows:glucose 1.8 mmol/L,lactose 3 mmol/L,peptone 10 g/L,yeast extract 5 g/L and NaCl 10 g/L.The HPLC results suggested that the production of L-5-methyltetrahydrofolic acid induced by autoinduction medium was nearly same with those induced by IPTG.