Chia Derived Peptides Affecting Bacterial Membrane and DNA: Insights from Staphylococcus aureus and Escherichia coli Studies

The increasing concern over microbial resistance to conventional antimicrobial agents used in food preservation has led to growing interest in plant-derived antimicrobial peptides (AMPs) as alternative solutions. In this study, the antimicrobial mechanisms of chia seed-derived peptides YACLKVK, KLKKNL, KLLKKYL, and KKLLKI were investigated against Staphylococcus aureus (SA) and Escherichia coli (EC). Fluorometric assays and scanning electron microscopy (SEM) demonstrated that the peptides disrupt bacterial membranes, with propidium iodide (PI) uptake reaching 72.34% in SA, calcein release of 98.27%, and N-phenyl-1-naphthylamine (NPN) uptake of 84.35% in EC. Increased membrane permeabilization was observed at concentrations above 5 mg/mL. SEM results further confirmed significant morphological changes, supporting the observed membrane damage. Additionally, the peptides showed intracellular activity by altering EC DNA mobility, suggesting a secondary antimicrobial mechanism through DNA interaction. These results indicate that the peptides are promising antimicrobials with potential mechanisms beyond membrane disruption, highlighting the need for further research to comprehensively understand their antimicrobial mechanisms.