Yield Determination of Bioethanol Production of Saccharomyces Cerevisiae Metabolic Process by Mathematical Modelling and In-Vivo 13C-NMR

An important step toward renewable and sustainable alternative energies is the replacement of liquid fossil fuel with biomass fuels such as bioethanol. The technology involved in ethanol bio-conversion from sugars derived from lignocellulosic biomass needs to be improved. Saccharomyces cerevisiae is one of the main organisms involved in the fermentation technologies. In order to maximise the ethanol yield during the fermentation it is of key importance to further understand the metabolic behaviour of Saccharomyces cerevisiae. The large number of interactions within a complex system such as a yeast cell requires the development of an approach able to deal with this complexity. In this paper, we applied an approach based on the combined use of in vivo NMR and mathematical modelling in order to analyze the response to ethanol stress in a wild-strain of Saccharomyces cerevisiae. We developed a model able to describe the modulation of the whole system induced by an external stress due to increasing concentrations of exogenous ethanol. This approach was able to interpret the experimental results in terms of metabolic response to exogenous ethanol in the yeast. The robustness of the model enables it to work correctly at different initial exogenous ethanol concentrations