Bactericidal synergism through enterocin AS-48 and chemical preservatives against Staphylococcus aureus.

Aims: To determine the effectiveness of enterocin AS-48 on Staphylococcus aureus CECT 976 in combination with chemical preservatives at acidic and neutral pH.

Methods And Results: At pH 4.5, the activity of AS-48 increases in the presence of lactic acid (1.0%), acetic acid (0.5% and 1.0%), and citric acid (0.3% and 0.6%). This synergistic effect has also been observed during the first 8 h of incubation with benzoate (0.06% and 0.12%) and sorbate (2% and 3%). Interestingly, at pH 7, lactate (1%) increases the inhibitory effect of AS-48, reducing the S. aureus population by 6 log units compared with the control culture. At neutral pH, combinations of AS-48 and sodium tripolyphosphate, STPP (0.3% and 0.5%) also eliminate this pathogen after 24 h.

Conclusions: These results indicate that enterocin AS-48 could be applied in combination with a range of chemical preservatives in order to increase its efficacy in inhibiting S. aureus.

Significance And Impact Of The Study: This study supports the potential use of enterocin AS-48 as a biopreservative to control S. aureus in combination with other food-grade chemical hurdles.