Antimicrobial effect of combined preservatives using chestnut inner shell, cinnamon, and ε-poly-lysine against food-poisoning bacteria Staphylococcus aureus

Chestnut inner shell, cinnamon, and ε-poly-lysine (ε-PL) have been used for natural preservative of food grade, and combined preservatives (CP) has been formulated previously. This study examined whether Staphylococcus aureus growth could be controlled using CP in tryptic soy broth (TSB). CP inhibited S. aureus growth by about 5 log CFU/mL in TSB. The cell surface hydrophobicity, autoaggregation, and motility of S. aureus were slightly reduced by CP treatment. The expression of adhesion- and toxin-related genes in S. aureus treated with CP was reduced than that in the control treated with TSB. In addition, the inhibitory activity of the CP was visible through the SEM images. Therefore, the CP consisted of chestnut inner shell extract, cinnamon extract, and ε-PL had appropriate antibacterial effect against S. aureus and could be applied as antibacterial agents.