In-vitro activity of various antimicrobial peptides developed from the bactericidal domains of lysozyme and β-lactoglobulin with respect to Listeria monocytogenes, Escherichia coli O157, Salmonella spp. and Staphylococcus aureus

Antimicrobial peptides developed from proteins occurring naturally in food of animal origin offer properties for possible application as food additives or in the production of packing foils. The objective of this study was to examine the antibacterial in-vitro activity of peptides developed from the bactericidal domains of lysozyme and P-lactoglobulin with respect to relevant food-borne pathogens. The bactericidal activity was calculated as log (N-0/N-1), where N refers to the number of bacteria colonies after two hours of Incubation at 37 degreesC, without (N-0) and in the presence (N-1) of antibacterial peptides. The peptides P106-112-NH2, P107-112-NH2, HR-H2 and HBSO55-64 showed strong antimicrobial activity with respect to S. aureus, L. manocytogenes, Salmonella spp. and E coli O157. No significant variation of bactericidal activity was observed for P106-112-NH2 and HP-H2 at different pH values. However. the pH affected the activity of CP-H2. Furthermore, the peptides P106-112-NH2 and HP-H2 were not affected significantly by various heating processes, although heating CP-H2 at 63 degreesC or 100 degreesC enhanced its bactericidal activity. The peptides P106-112-NH2. P107-112-NH2 and HP-H2 derived from lysozyme are potentially useful for reducing food-borne pathogens.