Effects of Temperature Induction Modes on the Plasmid Copy Number in Escherichia coli

Study on the temperature induction system of E. coli shows that the choice and change of induction temperature is important to heterologous gene expression, and the direct factor is shown in the effect on the plasmid copy number. This study focuses on effects of different temperature induction modes on the plasmid copy number using recombinant DH5a to express proapo AI-Milano. A novel two-step temperature-upshift induction is proved to be valuable in improving plasmid copy number, resulting in the significant enhancement of the expression level of recombinant protein.