抄録
Thermal inactivation kinetics of Escherichia coil β-galactosidase in phosphate buffer was studied for further understanding of non-linear patterns of the thermal inactivation of microorganisms. Thermal inactivation kinetics of the enzyme at constant temperatures were nonlinear; a semilogarithmic plot of residual activity vs. time was upwardly concave. The rate of inactivation was higher at higher pHs, lower phosphate concentrations, or higher temperatures. These inactivation patterns could be well described with a mathematical model. The model consisted of two sequential inactivation processes, each of which follows first-order kinetics. The effects of the temperatures on the values for the model parameters were then analyzed. The inactivation pattern of the enzyme at linearly increasing temperatures was sigmoid. This pattern was almost the same as that predicted with the model.
