D-氨基酸氧化酶基因在大肠杆菌中的诱导表达

The Expression of D-amino Acid Oxidase Gene in the Escherichia Coli

利用乳糖代替IPTG作为诱导剂,对重组大肠杆菌BL21(DE3)/pWY中的D-氨基酸氧化酶进行诱导表达。分别研究了乳糖浓度、菌体浓度、诱导温度、诱导时间对DAAO酶活的影响。结果显示,当菌浓OD600达1.0左右、乳糖浓度为10 g/L、28℃下诱导约6 h,摇瓶发酵得到的DAAO酶活高达2 400 IU/L,在5 L自控式发酵罐上酶活达3784.32 IU/L,比摇瓶提高了1.57倍。

The lactose was use as inducer substitute IFFG for expression of D - amino acid oxidase gene （daao） in the recombinant Escherichia coliBL21 （DE3）/pWY. The influences such as lactose concentration, cell density,the time of induction, the induction temperature on expression of the recombinant protein were investigated. Under the condition of the optical density at 600nm reached about 1.0,lactose concentration was 10g per liter, induced 6h at 28℃ ,the DAAO enzyme activity reached up to 2400IU per liter in shaking flask. In 5L fermentor the DAAO enzyme activity reached about 3784.32IU per liter,which was 1.57 times of in shaking flask.