Exploring the macin family of antimicrobial peptides: structure, function, and emerging applications in food safety

Rising levels of antimicrobial resistance (AMR) among foodborne pathogens is an increasing threat to food safety and product quality, driving the search for effective natural alternatives to conventional preservatives. Antimicrobial peptides (AMPs) have emerged as promising candidates for food preservation because of their broad-spectrum activity, diverse mechanisms of action and lower propensity for resistance development. Within this group, the macin family represents a promising yet underexplored class of cysteine-rich AMPs characterised by eight conserved cysteine residues that form four disulfide bonds. Macins have been identified across diverse taxa, including leeches, bivalves, gastropods, and hydrozoans and exhibit diverse antimicrobial mechanisms ranging from bacterial aggrelgation mediated by hydrophobic and electrostatic interactions and membrane permeabilization. This review provides a comprehensive synthesis of current knowledge of the macin family within the broader landscape of AMPs, highlighting their structural diversity, mechanisms of action and potential applications. Collectively, these characteristics suggest that macins may represent promising candidates for controlling resistant foodborne pathogens while maintaining product quality.