Bioprocess Engineering


The focus Bioprocess Engineering deals with the systematic characterisation of bioreactors (oxygen transfer rate based on geometry, oxygen transfer matix and macro mixing), the optimisation of bioprocesses to produce recombinant protein in bacterial and yeast host system and to establish co-culturing of extremophile organism to gain active pharmaceutical secondary metabolites.

Actual research activities

Characterization of bioreactors

Fermentations processes are developed in laboratory scale and have to be scaled up for production to fit the larger bioreactors in a plant. Thus parameters like kLa, Re-number, OTR etc. have to be considered.  In this research project a formula was established based on geometry and power input of the bioreactor to scale those parameter up by calculation which are scale dependent.

Optimization of bioprocesses

The scope of this project is to establish a process to gain an almost water-insoluble human protein which is produced by a yeast strain (Pichia pastoris) from the fermentation without losing biological activity. The protein (humane vitamin D receptor) that is associated to the nucleus membrane is produced by a genetically modified yeast strain intracellularily. Recovering the protein and solubilizing it is the biggest challenge in this process. Testing for stability is a two step approach: first the correct folding of the protein is analyzed by marking it with a flourophor, second a cell cultural test system is used to check for the biological activity. The development of this process should better the knowledge about solubilizing hardly soluble proteins.


Many microorganisms in nature are associated with others and therefore only show their full potential thus the full variety of secondary metabolites if cultivated under the same conditions (either in symbiosis or competitive). This project comprises experiments to determine the protein setup of each single organism in comparison to co-cultivated ones. Those secondary metabolites are isolated, characterized and tested by cell culture systems for their pharmaceutical activity.

Mission oriented research

Optimization of a fermentation process for a biotech startup. A fermentation process that tended to produce inclusion bodies (misfolded hardly soluble protein) was altered by the physical operating parameter to gain protein in soluble form.

Fermentation Training: a basic and a advanced fermentation training course are done for scientific personal to teach them how to use a bioreactor. This project is done in cooperation with Eppendorf.