Modeling and analysis of ethanol production in Escherichia coli

The ethanol production for biofuels is meant to be increased in the next years, but the yield could be improved. The goal of this study is to build a model of Escherichia coli KO11 to perform a rational design to improve the yield of ethanol production. The model was written in Cell Designer. The kinetic equations were picked up from the literature, with their kinetic parameters. All parameters of the equations couldn’t be directly extracted from the literature, and the initial metabolite concentrations couldn’t be found in the literature, due to thermodynamical infeasibility or incompleteness of data. Flux balance analysis was used to determine the steady state fluxes and a thermodynamical analysis determined the metabolites concentration. Together these data allows computations of missing paramaters. The metabolite time course was governed by mass-balance equations and the system could be solved numerically. The main results are the enzyme maximal rates and the thermodynamically feasible initial concentrations. The next step was to correct the model for stability. Differents ways were explored to obtain stability of the model, but they failed