Enhancement of prodigiosin synthetase (PigC) production from recombinant Escherichia coli through optimization of induction strategy and media.

PigC is a synthetase that catalyzes the condensation of 4-methoxy-2,2'-bipyrrole-5-carboxyaldehyde and 2-methyl-3-amylpyrrole to produce prodigiosin, which has a wide variety of impressive biological properties. In this study, we optimized PigC production from engineered Escherichia coli BL21(DE3). Investigation of different induction strategies revealed that autoinduction was the most appropriate method for PigC expression. As a result, PigC activity was elevated to 75.7 U/mL, nearly 2.1-fold higher than that with induction by isopropy-β-d-thiogalactoside. To achieve maximum enzyme production, the automedium components were optimized. "Single-factor experiments" showed that PigC production was greatly affected by the concentrations of glucose, yeast extract, and lactose. The Box-Behnken design for response surface methodology was then used to determine the optimal concentrations of these three components. According to a statistical approach, the optimum values of the three most influential parameters were 0.73 g/L glucose, 13.17 g/L yeast extract, and 5.86 g/L lactose. In the optimized automedium, the best PigC activity was obtained at 179.3 U/mL, which was 2.4-fold higher than using the initial medium. This study maximized PigC production as a foundation for further study and future industrial application.