Antimicrobial peptides (AMPs), whether synthetic or natural, have attracted considerable public interest since the emergence of pathogenic bacterial strains that are resistant to conventional antibiotics. In this context, our project aims at the synthesis of solid phase peptides, which are shorter fragments of natural antimicrobial peptides with the smallest unit that retains AM properties. Our goal is to synthesize highly effective antimicrobial substances based on natural peptides isolated from marine organisms. Our starting point is the aurelin AMP isolated from the cnidarian Aurelia aurita with antibacterial activity against Gram-positive (Listeria monocytogenes) and Gram-negative (E. coli) bacteria. We want to investigate and clarify the nature and exact mechanisms of the antibacterial action. One of our targets will be MurNAc pentapeptide translocase I (MraY), an enzyme that is essential for bacterial survival. We will design peptide structures with different moieties that have been shown to have antimicrobial activity. We will determine the activity of these molecular structures and their mode of action. The fundamental innovation of our project is a unique way to create combinations of desirable antimicrobial properties using peptide structures formed by the combination of natural AMPs and synthetic enhancements.