The main emphasis of the working group “bio-ag” lies in the development of integrated bioprocesses, where upstream, bioreaction, and downstream stages are closely linked to each other. From a biological point of view photo-biotechnology is in the centre of interest as well as processes, where the particulate properties play an important role. The main technical means are fermentation under highly controlled conditions, mathematical modelling of bioprocesses including measurement of intracellular compounds, as well as mechanical separation methods arising from downstream processing.
Microalgae are natural producers of valuable compounds like polysaccharides, pigments, or polyunsaturated fatty acids. For better understanding of growth and product formation under different light and media conditions experiments under highly controlled conditions in special photo-bioreactors are performed and mathematical models are developed. Moss cells have recently been recognized as ideal producers of recombinant proteins with respect to glycosilation and process safety. Phototrophic growth in bioreactors is investigated from laboratory to pilot scale. Beside evaluation of growth parameters GMP related process design is under consideration.
Production of valuable compounds from more or less cheap raw material is the major goal of the Particle-Biotechnology. However, there are several aspects where the properties of medium, cells, and products as particles play an important role in process design. These include the mechanical separation of cells, macromolecular compounds like polysaccarides or proteins from fermentation suspension, as well as the ability of cells to produce spatial structures.
Separation from fermentation broth, especially of polysaccharides, can substantially be enhanced by Electrofiltration, where an electrical field is applied in order to increase separation velocity to commercially interesting values. The patented approaches is looking for further industrial application. Magnetseparation is a novel tool to couple the affinity of proteins to microbeads with the possibility to employ the strong magnetic forces for bioseparation. This approach is being developed for lager scale and applied to real bio-processes for in-line product recovery.
