Extreme conditions are expected during sugarcane ethanol production that make the process difficultto be modelled. Saccharomyces cerevisiae cells deal with many stressful factors during fermentation,such as high-cell density, inhibitory compounds, lack of essential nutrients, non-aseptic conditions,and high temperature. Despite a substantial number of studies regarding the development ofmathematical models in recent years, the dynamic behavior of the process is not well comprehendedunder these stressful environments and constantly changing conditions. In this regard, this studyaims to develop a mathematical model for the alcoholic fermentation process in a fed-batchbioreactor under conditions that mimic first-generation (1G) ethanol production in Brazil. Thismodel will consider the thermal effects, energy balances, and substrate concentrations in the kineticparameters of the process. Furthermore, we aim to fulfill the lack of experimental data regarding theheat released during cellular growth and ethanol production, applying a calorimetric analysis of theprocess under specific metabolic stages achieved via chemostat cultivations. For that, we proposethe calorimetric investigation of the widely used industrial S. cerevisiae strain PE-2 using thevalidated setup reported by Schubert et al. (2007) in five distinct metabolic stages that decouplegrowth and ethanol production as far as possible to analyze them separately and determine theirreaction enthalpies experimentally. This project also aims to validate energy and mathematicalmodelling in the industrial 1G ethanol production using previously developed synthetic molasses.Therefore, the proposed model complements the literature by accounting for the impact of essentialprocess variables and the inclusion of energy balances on the traditional mathematical modelparameters.
News published in Agência FAPESP Newsletter about the scholarship: