Towards Modelling of an Industrial Aspergillus oryzae Aerobic Fed-batch Fermentation Process – Process Characterization Across Scales

In well-established fermentation processes, meaningful improvements in process performance can be achieved through real-time simulation and optimization. Thus, modelling is an essential tool to transform process data towards relevant predictions of variables. This contribution shows the characterization of an Aspergillus oryzae fermentation process, marked by significant batch-to-batch variation, both at production and pilot scales. The aim is to understand the impact of process variables and parameters on fermentation process performance for model development. Particularly, since it is a filamentous fungi fermentation, knowledge of biomass concentration and rheology is crucial for successful simulations since the viscosity of the fermentation broth rises due to the organism's morphology, leading to lower mass transfer as biomass concentration increases. Firstly, the biomass concentration and viscosity levels were analysed in the industrial-scale process. Furthermore, the on-line process data were analysed to identify potential sources of batch-to-batch variation in production. Additionally, the process has been scaled down to pilot scale for detailed investigation of important process parameters regarding feeding settings and agitation power. Overall, the data collection and analysis done thus far provides the basis for model development and testing.