EFFECT OF CARBON-DIOXIDE, OXYGEN, AND THE IR GAS-MIXTURE ON THE GROWTH OF SOME FOOD-BORNE PATHOGENS AND SPOILAGE BACTERIA IN MODIFIED ATMOSPHERE PACKAGE OF FOOD

The effect of ratio of carbon dioxide and oxygen on the growth of 16 s trains of food-borne pathogens and spoilage bacteria was investigated using the smear plate method. The results were as follows. 1) Growth o f facultative anaerobic bacteria (A. hydrophila, B. cereus, E. coli, E . cloacae, L. monocytogenes, S. liquefaciens, S. typhimurium, S. aureu s) was not completely inhibited by carbon dioxide, oxygen and their mi xtures. However, the growth rate of those bacteria was reduced in prop ortion to the increase in the ratio of carbon dioxide in the gas mixtu res. 2) Growth of microaerophilic bacteria (L. viridescens) was not af fected by carbon dioxide, oxygen or their mixtures. 3) Growth of the f ive species (A. calcoaceticus, F. lutescens, P. aeruginosa, P. fluores cens, P. fragi) of aerobic bacteria was not recognized in the presence of 100% carbon dioxide, while M luteus grew to some extent under the same conditions. Growth of P. fragi was inhibited in the presence of 3 0% or more carbon dioxide. The growth of F lutescens was observed only in the case of 10% carbon dioxide and 90% oxygen. The susceptibility of aerobic bacteria to carbon dioxide was higher than that of facultat ive anaerobic bacteria and microaerophilic bacteria. 4) Growth of anae robic bacteria (C. perfringens) was inhibited in the presence of oxyge n regardless of its concentration. From these results, it is clear tha t carbon dioxide, oxygen and their gas mixtures can be used effectivel y to inhibit or delay bacterial growth.