VOLUME 71 : 2023

In this work, a Response Surface Methodology (RSM) involving Central Composite Designs (CCD) have been successfully applied to study in buffer system the effect of temperature of incubation (X1), NaCl concentration (X2) and pH (X3) on the rate of autolysis of Lactococcus lactis LCL strain. The mathematical relationship of the autolysis rate related to the three significant independent variables was realized by a satisfactory fit model. Predicted values were found to be in a good agreement with experimental values, displaying a satisfactory coefficient of determination R2 = 0.9586, demonstrating a good significance of proposed model. The result of optimization predicted by the model show a maximal autolysis rate, when the optimum combination of temperature, pH and NaCl concentration, are respectively at 25 °C, 7 and 52 g/L. The validation of the predicted model has been conducted by executing three more experiments at the optimal levels, confirming its robustness.