FOR 5730:  Customized Deep Eutectic Solvents for Biocatalysis – a circular approach from molecular interactions to process parameters – (DESMOL2PRO)

• Subject Area: Thermal Engineering/Process Engineering ; Chemistry
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 528814716

Deep eutectic solvents (DES) are a very potent class of solvent systems that offer a variety of advantages in (bio)chemical conversions due to their specific properties, incl. a considerable depression of the melting point. Typically, a mixture of a hydrogen bond donor and a hydrogen bond acceptor is used and the resulting liquid form is consequently structurally different from classic molecular systems. These differences in solvent behavior are particularly advantageous for enzyme-catalyzed reactions, as they may enable higher stabilities and activities, among others. The ample design space for generating application-specific DESs allows the adjustment of water content, solubilizing of high concentrations of substrates/products, and designing downstream processing options for a specific need. The main hypothesis is that DES will fundamentally affect two critical aspects of bioprocesses, namely the reactivity and stability of biocatalysts and the downstream processing. Development and intensification of bioprocesses therefore require a different approach than classical processes using aqueous, organic and multi-phasic systems and, most importantly, require seamless integration of different disciplines. We will address two aspects by taking a holistic circular approach first to understanding and then to developing efficient and simultaneously sustainable processes. The circular strategy will lead to gaining a deep understanding while designing from molecules to processes and vice versa. All decisions for using application-specific DESs in biocatalysis must be included in an integrated process design, which comprises the theoretical, synthetic, and engineering research areas. This is made possible by a combination of investigation methods in the areas of computational fundamentals on the behavior of DESs and interactions with the protein (Computational Unit), the actual application of tailor-made DESs (Biocatalysis Unit) up to the final process control including downstream processing (Engineering Unit). The following central challenges are examined in this study to gain new insights into DES-based biocatalytic reaction systems: 1) Shifting away from predominantly empirically driven studies to the integrated use of predictive methods, both solvent- and protein-based, with a concurrent consideration of reaction and process engineering tasks. 2) Increase of the currently low understanding of structure-function relationships of enzymes in different solvents by systematic investigation of fitness landscapes of enzymes and catalytic peptides. 3) Understanding and controlling solvent properties during downstream processing with the clear aim of recovering and reusing DES-based solvent systems. As the chosen research approach naturally requires close interdisciplinary cooperation between experts from modeling, catalysis, technical chemistry, and process engineering, a diverse team of scientists from different locations has been assembled.

• DFG Programme: Research Units
• International Connection: Austria

Projects

• Coordination Funds (Applicant Kara, Selin )
• Engineering of (continuous) biocatalysis in customized DES mixtures (Applicant Gruber-Wölfler, Heidrun )
• FAIR research data management: Thermophysical properties and enzyme kinetics in deep eutectic solvents (Applicant Pleiss, Jürgen )
• Integration of selective separation techniques for the continuous reuse of deep eutectic solvents (Applicant von Langermann, Jan )
• Kinetics and mass transfer analyses of biocatalytic oxygenations and decarboxylations in deep eutectic solvents (kinetics & mass transfer of biocatalysis in DESs) (Applicant Kara, Selin )
• Molecular simulation of thermophysical properties for enzyme catalysis in DES-based solvents (Applicant Hansen, Niels )
• Mutational landscapes of enzymatic solvent preference (Applicant Kourist, Robert )
• Online analytics for reaction mixtures and characterization of enzymatic (de)carboxylation at ambient and high pressure in DESs (Applicant Liese, Andreas )
• Synthesis and characterization of catalytic properties of heme-binding peptides with peroxidase activity in deep eutectic solvents (Applicant Holtmann, Dirk )

• Spokesperson: Professorin Dr.-Ing. Selin Kara