Staphylococcus aureus growth and its enterotoxin production in sterilized milk were modeled with a modification of a new logistic
model recently developed by us. The modified model and the Baranyi model described the early exponential phase of a growth curve
more accurately than the previousmodel, at constant temperaturesfrom 14 to 36.5 1C. The amount of toxin in milk increased
linearly with time from the time the cell population reached about 106.5 cfu/ml. The rate of toxin production linearly increased at
temperaturesbetween 14 and 32 1C. From parameter values obtained at the constant temperatures, the model successfully predicted
bacterial growth in the milk at a varying temperature. For toxin level estimation, we postulated that the rate of toxin production
might be regulated with the temperature after the cell concentration reached 106.5 cfu/ml; the time point when the cell concentration
reached that value waspredicted with the modified growth model. Introduction of a correction factor in the toxin estimation
successfully predicted the toxin level in milk at a varying temperature. These results showed that this prediction system consisting of
the modified model and the toxin production algorithm might be a useful tool for modeling bacterial growth and its metabol