Modeling of Baker's Yeast Bioreactor in Batch and Fed-Batch Culture

A structured unsegregated cybernetic model is able to describe diauxic growth phenomena of cells colony in aerobic condition. This model shows that the metabolic activity of the cells is regulated by internal cellular controls which direct the micro-organism towards the most convenient metabolic pathway able to optimize the use of available resources. In this paper, for proving this reality, a structured unsegregated cybernetic model have been used for describing of the growth stages of Saccharomyces cerevisiae on mixed substrates. The results of simulation of baker’s yeast in batch and fed-batch bioreactor show that agreements are quite satisfactory between experimental data and simulation results. And it well performs in the simulation of the lag-phases and the diauxic growth. Finally, for preventing of oxygen starvation that causes ethanol production, oxygen mass transfer coefficient is simulated on the function of impeller speed and air flow rate and the effect of this parameter on biomass yield have been discussed.