Optimization of antimicrobial activity of surfactin and polylysine against Salmonella enteritidis in milk evaluated by a response surface methodology.

In this article, the sensitivity of Salmonella enteritidis to surfactin and polylysine was observed, and the optimization of antimicrobial activity of surfactin and polylysine against S. enteritidis in milk was evaluated by a response surface methodology. Results showed that S. enteritidis was very sensitive to them, whose minimal inhibitory concentrations were 6.25 and 31.25 μg/mL, respectively. The optimization result indicated that S. enteritidis could be sterilized by 6 orders of magnitude when the temperature was 4.45°C, the action time was 6.91 h, and the concentration (surfactin/polylysine weight ratio, 1:1) was 10.03 μg/mL.