Recombinant Protein Secretion for Production and Purification in Bacterial Systems

The Escherichia coli bacterial expression system was the first platform developed for recombinant protein production and remains the fastest, simplest, and most cost-effective system for achieving high protein yields for fundamental research, as well as biotechnological and pharmaceutical applications. Bacterial surface display systems and secretion of target proteins have become widely used approaches. These strategies help prevent intracellular aggregation and proteolytic degradation of recombinant proteins, enabling the recovery of soluble, properly folded, and stable protein products. In the case of toxic proteins, secretion mitigates their inhibitory effects on essential host cell processes. Furthermore, secretion of target proteins and peptides significantly simplifies their purification. The review summarizes the data on E. coli secretion systems with a special focus on protein export and display strategies, and discusses their applications in scientific research, industrial biotechnology, and medicine.