Effect of potassium sorbate with and without added antioxidants on Staphylococcus aureus 196, S-6, 137 and 326 in a liquid system was evaluated. We found (a) potassium sorbate a 1, 3, and 5% levels in combination with BHA, BHT, PG (50 and 100 ppm) exerted greater bactericidal and bacteriostatic effects on S. aureus strains at pH 5 than at pH 7; at pH 6 the effect was more pronounced at 3 and 5% compared with 1% sorbate, (b) TBHQ was highly inhibitory to S. aureus strains with or without the addition of sorbate, (c) in combination with sorbate, BHA exerted greater bactericidal effects compared with BHT and PG, (d) higher concentration of antioxidants exerted more bactericidal and bacteriostatic effects on test organisms, (e) S. aureus S-6 was more resistant than 196, 326, and 137 in the presence of sorbate and antioxidants and (f) shake cultures of S. aureus grew better than static cultures in the presence of sorbate and BHA.
1Contribution No. 81-105-j, Department of Animal Sciences and Industry, Kansas Agriculture Experiment Station, Manhattan, Kansas 66506.
2This work is supported in part by a grant from Monsanto Corp., St. Louis, MO.
3Lahellec was a guest scholar at the Kansas State University, March–April, 1980. She is the Associate Director of Poultry Experiment Station, Pluofragan, France.