A predictive model for the growth rate of Bacillus cereus in broth by response surface methodology

Abstract

A response surface methodology (RSM) was developed for predicting the growth rate of Bacillus cereus in a tryptic soy broth medium as a function of temperature (10 to 40A degrees C), pH (5.5 to 8.5), and the NaCl concentration (0 to 8%). The primary model showed a good fit (r(2) = 0.920 to 0.999) to a Gompertz equation to obtain growth rates each condition. The quadratic polynomial model was found to be significant (p < 0.0001) and predicted values were found to be in good agreement with experimental values (R-2 value of 0.9486). The evaluation of RSM for describing the growth rate of B. cereus used the bias factor (B-f) and the accuracy factor (A(f)). Both the B-f value (1.11) and the A(f) value (1.50) were within acceptable ranges. This model was provided an efficient and accurate method for predicting the growth of B. cereus as a function of the controlling factors.