Recombinant Production of Caspian Trout (Salmo caspius) Hepcidin in Escherichia coli and Evaluation of its Antibacterial Activity

Antimicrobial peptides are promising therapeutic agents due to their broad-spectrum activity against microbial pathogens. In this study, the recombinant antimicrobial peptide hepcidin from Caspian trout (Salmo caspius) was produced using an Escherichia coli expression system. The coding sequence of the mature CtHep peptide was codon-optimized for E. coli, cloned into the pET32c(+) vector, and expressed as a fusion protein. The recombinant protein was expressed as inclusion bodies, purified using a HisTALON™ affinity column, and refolded under optimized conditions. The thioredoxin-CtHep fusion protein was cleaved using TEV protease, and the recombinant CtHep peptide was isolated and analyzed. The antimicrobial activity of CtHep was evaluated against Bacillus subtilis, Micrococcus luteus, and Escherichia coli using the microdilution method. The results demonstrated that recombinant CtHep exhibited significant inhibitory effects on both Gram-positive and Gram-negative bacteria. These findings highlight the potential of recombinant CtHep as an antimicrobial agent for applications in aquaculture and other industries. Furthermore, the optimized conditions for E. coli cultivation and the methods used for the production and refolding of the recombinant CtHep peptide in this study can be applied in future research on the recombinant production of antimicrobial peptides in E. coli.