Fig. 4
Effect of Inducer (IPTG) concentration, temperature, and post-induction duration on serratiopeptidase expression in E. coli C43(DE3) cells. a Representative 12% SDS-PAGE (section-1) gel showing the effect of inducer concentration on recombinant serratiopeptidase expression at different concentrations of inducer ranging from 0.1 to 2.0 mM. Section 2 of the image shows the plotted bar graph of average protein expression at different inducer concentrations obtained from the densitometric analysis of three independent SDS-PAGE gels. b Section 1 represents a 12% SDS-PAGE gel showing the effect of temperature on mature version serratiopeptidase under uninduced condition (uninduced lane) while other lanes represent induced cell lysates at different temperatures viz—37 °C, 30 °C, 25 °C, and 18 °C. Section 2 is the plotted bar graph showing the effect of post-induction duration on the expression of mature recombinant serratiopeptidase. The expression was measured from three independent sets of experiments and represented in the form of the average value of them, showing the percentage expression of mature serratiopeptidase in terms of total intracellular protein expression visualized on the SDS-PAGE gel