Effect of salt and temperature on the growth of Escherichia coli PSII

Abstract

AbstractPresence of pathogenic strains of Escherichia coli in foodstuffs may pose a health risk for a consumer. Therefore, knowledge on the effect of environmental factors on the growth ability of E. coli is of great importance. In this work, the effect of incubation temperature (6–46 °C) and the combined effect of temperature and water activity (0.991–0.930) on the growth dynamic of E. coli PSII were analysed. Based on the growth curves obtained, growth parameters were calculated by using the Baranyi D-model. Growth parameters were further analysed in secondary phase of predictive modelling. Using the CM model that describes the effect of combined factors, cardinal values (Tmin = 4.8 ± 0.4 °C, Topt = 41.1 ± 0.8 °C, Tmax = 48.3 ± 0.9 °C, awmin = 0.932 ± 0.001, and awopt = 0.997 ± 0.003) for the isolate were calculated. Under optimal conditions, the specific growth rate is µopt = 2.84 ± 0.08 h−1. The results obtained may contribute to the assessment of the risk associated with the possible E. coli presence in raw materials and to the search for preventive measures with defined degree of accuracy and reliability.