基因重组大肠杆菌表达类人胶原蛋白诱导条件优化研究

Study on Induction of Recombinant Escherichia coli for Producing Human-like Collagen

为了提高重组大肠杆菌BL 21高密度发酵生产类人胶原蛋白的产量,分别研究了诱导时 机、乙酸浓度、诱导强度以及补氮方式对外源基因表达的影响,并对各因素进行了优化。采用补 料-分批式发酵,初始装液体积为6L。最终细胞密度可达到84.3g／L,类人胶原蛋白的表达量为 14.6g/L。结果表明:在对数生长的中后期进行诱导,尽量减少乙酸的积累量,42℃诱导3h后降温 至39℃继续诱导,并采用每隔10min补36ml补料氮溶液的周期操作方式,有利于细胞的生长和 外源蛋白的表达。

The effects of induction opportunity, acetic acid concentration, induction strength and nitrogen-feeding strategy on high cell-density fermentation of recombinant Escherichia coli for producing human-like collagen were investigated. By adopting Fed-batch cultivation, the initial broth volume was 6L. The cell density could reach 84.3g/L and the human-like collagen yield was 14.6g/L. The results demonstrated that it was beneficial to cell growth and foreign gene expression when induction was made in near end of logarithmic phase, the acetic acid accumulation was reduced, temperature was shifted to 42℃ to induce and decreased to 39℃ to continue induction after three hours, and the nitrogen solution was fed 36ml with 10mins interval.