正交实验优化RGD-蛛丝蛋白基因工程菌高密度发酵条件

Optimization of the Conditions of High Cell Density Fermentation by Orthogonal Test for the Engineering Bacterial Strain with RGD-spider Silk Protein Gene

通过正交实验对RGD-蛛丝蛋白基因工程菌高密度发酵条件进行优化.选择pH、温度、诱导剂、前体物甘氨酸/丙氨酸4因素,分别在3个水平上进行考察.当菌体密度OD600 nm为35左右时,添加IPTG诱导5 h,确定了发酵诱导条件为前体物甘氨酸/丙氨酸质量浓度为0.5%,诱导剂IPTG浓度为0.4 mmol/L,pH为7.0,温度为37℃.工程菌密度OD600 nm可达到53.1,目的蛋白比例可达到24.3%,每L发酵液菌体经纯化可得到410 mg的目的蛋白.

Optimize of the conditions of high density fermentation for the engineering bacterial strain pNSR-16/BL21 （DE3） pLysS by orthogonal experiment. Factors such as pH, cultivation temperature, inducer,and the concentration of Gly/Ala were selected and tested at three levels, respectively. The optimum conditions of the parameters were 0.5% Gly/Ala, 0.4 mmol/L IPTG, pH 7.0 and 37℃. The optical density of OD600 nm and the target protein could be achieved at 53.1 and 24.3 %, respectively, and target protein feeded 410 mg per litre medium.