ИСТИНА

Microbial contamination of foods leads to food poisoning in consumers. The uncontrolled application of antibiotics in animal husbandry, which is the case for the developing countries in general, generates their global environment accumulation and the formation of antibiotic-resistant strains. This problem can also refer to food preservatives obtained by chemical synthesis. On the other hand, fermentation and pickling are traditional cooking methods in most countries to prevent microbial spoilage. The producing organic acids are bacterial metabolites among which lactic acid (LA) and acetic acid (AA) should be mentioned. The minimum inhibitory concentration (MIC) is a quantitative measure of a substance impact on bacterial culture. A quantitative model describing the effect of MIC on the specific growth rate was used. The growth curves of three of the most common microbial contaminants (Bacillus cereus, Staphylococcus aureus, Salmonella enterica) were obtained under anaerobic conditions at different concentrations of LA or AA, which were added in the medium before inoculation separately. The specific growth rates were calculated by estimating the line of best fit. MIC and equation coefficients were calculated for each of the acids and each test culture. S. enterica was established to be most sensitive to both of the acids (MIC LA 2.25 mg/mL, MIC AA 1.77 mg/mL), while B. cereus are shown to be most resistant (MIC LA 3.48 mg/mL, MIC AA 3.20 mg/mL). The results obtained can be applied for assessment of fermentation and pickling effectiveness for foods preservation in the future.