B.5 Modelling and simulation reactive separation processes

The work in this research project is currently focussed on cultivations of filamentous fungi and of Saccharomyces cerevisiae. In the first project, structured process models are being developed to study key factors in the submerged cultures of filamentous fungi, i.e. Aspergillus oryzae for production of -amylase in high performance bioreactors. The simulation results with the developed models have been compared with experimental data. The results indicate that the influence of oxygen limitation on the process depends on the specific growth rate. The maximum specific productivity for -amylase is reached when the specific growth rate is about 0.15 h-1 (Dp). For specific growth rates below Dp, oxygen limitation takes place simultaneously on both biomass formation and enzyme production. For growth rates above Dp, a decoupling between the limitation on biomass formation and enzyme production is observed. Amylase production becomes more sensitive to the low levels of oxygen and decreases even though the biomass concentration remains constant.
Present and future work in this project is to improve the feature for estimation of model parameters, validation of the model by obtaining more experimental fermentation data.