Optimization of Expression of Recombinant K88 Fimbrial Subunit Protein in Escherichia coli

Response surface analysis(RSA) was applied to optimize the main parameters on expression of recombinant K88 subunit protein FaeG in Enterotoxigenic Escherichia coli. The results showed that three factors including induction starting time, IPTG concentration and inducing time,and their interactions all had significant effects on expression of recombinant FaeG(P 0.01). Further simulated optimization revealed that the percentage of recombinant FaeG protein in complete bacterial protein was 35.4% by adding IPTG 0.8 mmol/L and inducing 5 h after 2.5 h culture, improved by 28.7% compared with the production(27.5%) obtained under the conditions optimized by one-variable-at-a-time. It is concluded that RSA is an effective method to optimize the parameters such as induction starting time, IPTG concentration and inducing time in improving the expression of recombinant protein in E.coli.