Functionalization with oxygen is a key operation in various organic chemical syntheses. With regard to environmental protection and sustainability, replacing the currently used highly toxic oxidizing agents such as chromates by a catalytic introduction of hydrogen peroxide or molecular oxygen is highly desired. A variety of enzymes, e.g. lipases but also complex, industrially hardly implemented per- and monooxygenases enable these reactions under mild and selective conditions. Due to the lack of an appropriate technology that synchronizes both the specific features of oxyfunctionalization reactions such as highly reactive intermediates (H²O²) or low solubility of reactants in aqueous solutions (O²; most organic compounds), and the specific properties of biocatalysts such as mode of activity and susceptibility to detrimental effects of reactants and/or reaction conditions, bio-based oxyfunctionalizations are not yet used industrially.

Building on knowledge gained in two previous joint projects of the applicants on

• a) the lipase-mediated synthesis of peroxyacetic acid coupled with the subsequent spontaneous epoxidation of α-pinene and
• b) on the broad applicability and adaptability of continuous biocatalysis in Pickering emulsions, we propose that BioPE in a continuous membrane reactor could be a viable basis to accomplish biocatalyzed oxyfunctionalizations of organic compounds with a low water solubility.

We also suppose that both the formulation of the biocatalyst or its placement at the L/L interface, respectively, and the physical properties of the BioPE can be further optimized to increase the synthetic performance. Thus, the project BioOxy aims for the systematic investigation of Pickering emulsions regarding their suitability to promote (continuous) biocatalytic oxyfunctionalization reactions. This research will address the fundamental question if biocatalyzed oxyfunctionalizations benefit from implementation into Pickering emulsions and will identify and optimize key parameters (e.g. drop size, interfacial area, biocatalyst load, substrate supply, phase composition) that determine the reactions system. The interdisciplinary approach with partners from biotechnology and engineering enables in-depth understanding of the enzymatic and physicochemical processes in the reaction systems.

We expect that by knowledge gain on the influence of emulsion properties and composition a mathematical model can be developed to describe the reaction kinetics in BioPE and help finding the optimal technological conditions for an efficient reaction.

The outcome of the project can be the starting point for further research and development that will enable more enzyme-catalyzed oxyfunctionalizations to be implemented in industrial applications and made accessible for biochemical processes.

• Prof. Dr.-Ing. habil. Anja Drews (Projektleitung)

• Lemuel Onoriode Adomi (Projektmitarbeiter_in)

DFG

TU Dresden

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