MODELING BACILLUS-CEREUS GROWTH

The aim of this study was to model the growth, in a model system, of t oxigenic strains of Bacillus cereus as a function of temperature, pH a nd water activity. Optical density (OD) values were transformed into n umbers of colony-forming units (CFU) by the use of a 'calibrating' rel ation. The growth curves were then fitted to the Gompertz function whi ch allowed the estimation of the lag-time (lambda) and the growth rate (mu). These two parameters were then modelled according to the contro lling factors which were pH and water activity at 20 and 30 degrees C. (C) 1997 Elsevier Science B.V.