TERKIDA PRIFTI, LULJETA PINGULI, ILIRJAN MALOLLARI
Our research aims to study the fermentation process with free brewer’s yeast, Saccharomyces carlsbergensis, under industrial conditions. The study of the process will focus on determining kinetic constants, such as the maximum specific growth rate max and the half-saturation constant Ks, through the
Office package and MATLAB, because it is necessary at first to understand the growth kinetics of microorganisms. We know that the kinetics of the growth varies not only from the type of the microorganism but also from the type of the process, such as periodic or continuous, which affects the fermentation conditions. The knowledge of these constants is necessary for a further step to move to a pilot program, where the fermentation process will be carried out with free and/or immobilized yeast in periodic and continuous conditions. From the calculation of these quantities, we can predict the course of the fermentation process or the maturation of the beer in industrial conditions. During the estimation of these constants, the fermentation process progressed normally across all tanks, as evidenced by the substrate consumption observed over the course of the fermentation period. During the evaluation of the kinetic constants, temperature was found to have a considerable influence. Choosing an appropriate mathematical model is complex. By looking at the features of each theoretical model and comparing them with the experimental results, we can say that the Teissier model fits the data better.
Keywords : kinetic constants, fermentation, periodic process, mathematical models.