Chia derived peptides affecting bacterial membrane and DNA: Insights from Staphylococcus aureus and Escherichia coli studies Names and e-mail addresses for all authors

The rising concern over microbial resistance and the potential impact on human health of conventional antimicrobial agents commonly utilized in food preservation has led to the research of plant antimicrobial peptides (AMPs) and their mechanisms of action. Therefore, study investigated the antimicrobial mechanisms of peptides YACLKVK, KLKKNL, KLLKKYL, and KLLKI, derived from a chia seed peptide fraction, against Staphylococcus aureus (SA) and Escherichia coli (EC). The analysis incorporated fluorometric assays and scanning electron microscopy (SEM) to determine membrane permeabilization and bacterial cell morphological changes. The peptides disrupt bacterial membranes, as shown by a propidium iodide (PI) uptake of 72.34 ± 1.87% in SA, calcein release of 98.27 ± 0.93%, and N-Phenyl-1-naphthylamine (NPN) uptake of 84.35 ± 3.03%, in EC. At concentrations above 5 mg/mL, an increased effect on membrane permeabilization was observed. SEM results indicated marked morphological alterations, thus supporting fluorometric findings of cell membrane damage. Furthermore, changes in electrophoretic mobility of EC DNA indicated peptide-DNA interactions, suggesting a supplementary antimicrobial effect through intracellular target engagement beyond membrane disruption. These results highlighted the peptides as promising novel antimicrobial agents with the capability to disrupt bacterial cell membranes and potentially target DNA. The need for further exploration of the peptides' intracellular actions and comprehensive antimicrobial mechanisms is emphasized.