Effects of Potassium Sorbate Alone and in Combination with Sodium Chloride on Growth of Staphylococcus aureus MF-31

Effects of potassium sorbate alone and in combination with 2 or 3% sodium chloride on growth of Staphylococcus aureus MF-31 were examined. Growth studies were done in tryptic soy broth (final pH, 6.3) at 22°C for 15 d and 35°C for 48 h without shaking. A dual plating procedure was used to monitor growth (tryptic soy agar) and development of injury in the cell population (tryptic soy agar + 7% NaCl). At both storage temperatures, sorbate alone and in combination with 2 or 3% NaCl had only minimal effects on growth inhibition. Presence of NaCl did not appear to enhance effectiveness of sorbate in cell inhibition under these conditions. No injury was observed in the cell population.