(239e) Novel Enzymes and Separations in Biotechnology-Identifying a Process Tailored Extraction System-

The development of industrial scale bioprocesses has come into high scientific and industrial interest over the last decades. Especially in the red and white biotechnology, process costs are often dominated by 50 - 80 % by the downstream processing. Thus, novel separation technologies such as aqueous two-phase extraction using the TAPPIR Technology have come into focus. Extractions based on aqueous two-phase system (ATPS) were shown to have an enormous potential for the extraction of biomolecules due to a high biocompatibility and low operating costs. The most common ATPS consist of a hydrophilic polymer and a salt serving as phase-forming components. The distribution of the target protein within these systems can either be influenced by the choice of the phase forming components, and additionally by a choice of a displacement salt. It is essential to identify a suitable ATPS using profound knowledge on the molecular interactions in solution.

One promising and fast measure accounting for complex interactions of biological macromolecules is the second osmotic virial coefficient (B₂₂) characterizing the interactions between the biological macromolecules in solution and the cross virial coefficient (B₂₃) characterizing interactions of the biological macromolecules with the salts / impurities. Assisted by a thermodynamic modeling approach, identifying the interactions of the low molecular weight components in the extraction system, allows for a fast and reliable first estimate on an appropriate extraction system.

B₂₂ as well as B₂₃ data was measured using composition gradient multi angle light scattering (GC-MALS) for different proteins and salts in aqueous solution.

One additional advantage using this approach is the fact, that the partition coefficient can be estimated using a hybrid ShortCut Modell based on a minimal set of experimental data. The results will help to improve the development and optimization of ATPS as well as the TAPPIR Technology used for the design of an efficient downstream process.