GROWTH OF SELECTED FOOD SPOILAGE AND PATHOGENIC BACTERIA UNDER MODIFIED ATMOSPHERE

The effects of carbon dioxide on the growth of food spoilage and patho genic bacteria, Pseudomonas aeruginosa, P. fluorescens, Escherichia co li, Salmonella typhimurium, Vibrio parahaemolyticus, nonagglutinating (NAG) vibrio, Staphylococcus aureus, Bacillus cereus, B. subtilis, B. macerans, B. licheniformis, Weissella (Lactobacillus) viridescens, Ent erococcus faecalis, and Clostridium perfringens were investigated on s olid media at 30 degrees C. Growth of the bacteria on the surface of P late Count Agar (PCA) packaged with different concentrations of carbon dioxide (0, 20, 40, 60, 80, 100% in N-2 gas) was evaluated after 24 h incubation at 30 degrees C. Growth of P. aeruginosa, P. fluorescens, E. coil, S. typhimurium, V. parahaemolyticus, NAG vibrio, and S. aureu s was inhibited by carbon dioxide in proportion to the increase in the ratio of carbon dioxide in Nz gas mixtures. Particularly, a significa nt growth inhibition was observed for two species of Pseudomonas, S. a ureus, and NAG vibrio. Growth of 4 species of Bacillus (B. cereus, B. subtilis, B. macerans, B. licheniformis) was not inhibited by carbon d ioxide. Growth of 2 species of lactic acid bacteria (W. viridescens, E . faecalis) and a species of obligate anaerobic clostridia (C. perfrin gens) was stimulated by CO2.