Construction, cloning, and expression of Melittin antimicrobial peptide using Pichia pastoris expression system

With the emergence of antibiotic resistance, researchers have recently focused on antimicrobial peptides as potential drug candidates. In this study, Melittin, one of the most effective antimicrobial peptides of honey bee venom was produced by the expression system of Pichia pastoris GS115. Melittin was cloned into pPIC9 vector, transformed, and integrated into the P. pastoris genome. The highest level of expression was observed in BMM minimal medium without protein, pH 6, 2% methanol, and 48 h. Then, the recombinant Melittin was tested on some gram-positive and gram-negative bacteria to investigate the antimicrobial effects and showed widespectrum activity. The production of Melittin by this method costs very low and paves the way for further studies and also therapeutic usages.