Optimizing the expression of a Heterologous chitinase: A study of different promoters

Many relevant applications have been demonstrated for chitinolytic enzymes. However, their successful exploitation depends upon the availability of strains and expression conditions that allow the production of active forms and large quantities of these enzymes. Escherichia coli has been commonly used to express and overproduce different proteins, among them chitinases. Improving the functional gene expression of chitinases is key to exploiting their potential. In a recent study, we described the effect of various parameters on the functional expression of 2 chitinases from different families, demonstrating that the effect of each of these parameters on the activity of both chitinases was specific to each enzyme. In this study, the expression of a Lactococcus lactis chitinase encoded by a new allele, ChiA1-2, was optimized. The results showed that not only the expression parameters seemed to influence protein production, solubility and activity but also the plasmid used for the expression. Herein, we describe the effect of 2 different promoters, tac and T7, on the expression of the active form of the chitinolytic enzyme.