Antibacterial Activity of Cell-Free Culture Supernatant of Bacterioci-nogenic Pediococcus pentosaceus IO1 against Staphylococcus aureus Inoculated in Fruit Juices

Abstract

Background: Staphylococcus aureus is a major food-borne pathogen worldwide and a frequent contaminant of fruit juices. This study aimed to evaluate the antibacterial activity of bacteriocin-containing Cell-Free Culture Supernatants (CFCS) of Pediococcus pentosaceus IO₁ against S. aureus inoculated in fruit juices, as well as their impact on the juice sensory attributes.

Methods: The orange and watermelon juice samples were treated with bacteriocin supernatant at different concentrations (1, 5, and 10% v/v) and the sensory attributes were evaluated using a 5-point hedonic scale and thereafter inoculated with a culture of S. aureus. Then, the inhibitory effect of bacteriocin-containing CFCS of P. pentosaceus IO₁ against S. aureus in the fruit juices was evaluated by in situ and plate assays.

Results: The 10% (v/v) bacteriocin-containing CFCS exhibited the highest antibacterial activity, reducing S. aureuscounts in pasteurized orange and watermelon juices by 1.42 and 2.12 log Colony Forming Units (CFU)/ml, respectively, and by 1.03 and 0.88 log CFU/ml in unpasteurized orange and watermelon juices, respectively, compared to the control. The taste, colour, and overall acceptability of pasteurized orange and watermelon juices treated with 1% (v/v) bacteriocin supernatant and 0.1% (w/v) sodium benzoate were not significantly different (p=0.228) from those pasteurized orange and watermelon juices without preservative.

Conclusion: The bacteriocin produced by P. pentosaceus IO₁ could be used as a natural preservative in fruit juices to control S. aureus.