This study examines the kinetics of a batch fermentation process of raw juice, an intermediate product of
sugar beet processing, by free Saccharomyces cerevisiae yeast cells, with the aim of producing bioethanol.
Defining the kinetics and kinetic parameters of this bioprocess may be regarded as an important step
towards translating it to industrial scales (scale-up). The optimal values of the kinetic parameters were
determined by fitting the models into the experimental data, i.e. by minimising the discrepancy between
the model predictions and corresponding experimental data. The growth of yeast cells could be expressed
by a logistic function model, which describes the growth as a function of initial biomass concentration,
fermentation time, specific growth rate and final biomass concentration. The modified Gompertz model,
which gives the bioethanol production lag time, the maximum bioethanol production rate and the
maximum bioethanol concentration, was able to describe the formation of bioethanol as the fermenta-tion proceeded. These models thus can be employed for further development of the bioethanol produc-tion process from sugar beet raw juice