Escherichia coli strain engineering for enhanced production of serratiopeptidase for therapeutic applications

Serratiopeptidase is an extracellular zinc-containing metalloprotease that is produced by Serratia marcescens having molecular weight of about 53kD. It has shown therapeutic (anti-inflammatory, anti-fibrinolytic and analgesic) as well as industrial applications (detergents, food processing, leather, paper and brewing etc.). The evolution of Serratia marcescens as an opportunistic pathogen associated with various infections has led researchers to think and develop an alternate strategy for its industrial production. The study presents successful cloning, expression and purification of active serratiopeptidase, using Escherichia coli BL21 [DE3] and pET SUMO vector followed by optimization of synthetic media and culture conditions for enhanced serratiopeptidase production. Initial optimization of physical parameters was done followed by a screening of different carbon and nitrogen sources. The significant media components for serratiopeptidase production as shown by factorial screening experiment were subjected to Response Surface Methodology (RSM) based optimization. The optimized media yielded 86 mg L−1 of biologically active refolded serratiopeptidase from 20 g L−1 wet weight of induced pellet as predicted by the equation. The success of the application of a statistical model for designing an optimized media for enhanced serratiopeptidase production also suggests a new insight for the scale-up of serratiopeptidase towards industrial applications.