Effect of Temperature on the Growth of Recombinant E.coli and on the Expression of Recombinant Protein

The expression of rhCu/Zn SOD in recombinant E.coli BL21(DE3) at different induction temperatures was investigated. The growth of E.coli and the expression of the recombinant protein were studied and compared at 37°C or 30°C .The recombinant E.coli was cultivated in 5L fermentor, results of which showed that at 30°C the specific growth rate was reduced while the viability of recombinant E.coli and plasmid stability were greatly increased. The stability and solubility of the recombinant protein were also improved. The maximum enzyme activity of rhCu/Zn SOD expressed at 30°C was increased to 4 757 U/mL,which was 2.7 times as that at 37°C .