Optimization of Condition for Recombinant L-Isoleucine Dioxygenase Expression in Escherich coli BL21(DE3)

摘要

As an inducer, suitable concentration of IPTG is an important factor for cell growth and protein expression. We found that high concentration of IPTG could affect the growth of bacterial cells and 0.15 mmol/L IPTG is the most appropriate concentration for protein expression. Moreover, low temperature could inhibit growth of cells and thus decrease protein expression level, however, high temperature could inactivate intracellular coenzyme. Therefore, 37 °C is selected for the most appropriate temperature for protein expression. Furthermore cells cultivated for 4 h and induced for at least 6 h exhibited excellent protein expression level.