Abstract

Biocatalytic Transformations in Continuous Flow Reactors: Opportunities Opened up at the Microscale

Bernd Nidetzky, Head of Human and Biotechnology, Graz University

Biocatalysis has become a key technology for process development in the chemical and their allied industries. The use of enzyme-catalyzed synthesis promotes the development of inherently safe and sustainable processes and thus contributes to fulfillment of green chemistry principles at large. Conventional reactors for biotransformation research and development include stirred or shaken vessels as well as different types of column reactor. There is a clear trend towards continuously operated processes at the manufacturing scale. Microreaction technology has brought a wave of innovations to chemical process research and development, and has become a powerful engineering tool in the field. Interest has therefore been also high in integrating biocatalysis with microreaction technology. The use of microreactors could provide the biocatalytic process development with interesting new opportunities, including fast reaction screening and also process intensification as often quoted potential benefits. The talk will review recent progress in the field. Biotransformations operated continuously are usually built around immobilized enzymes. The defining feature of a microstructured reactor, that its operation involves fluid flow, implies that enzymes are preferably utilized in an immobilized state. Immobilization therefore constitutes a key unit operation in the development of biocatalytic microreactors. Known methods of enzyme immobilization may have to be adapted for use in microreactors. Non-covalent oriented immobilization of fusion proteins containing a binding module appended to the enzyme of interest presents a new development. Internal sensing is of great interest for development of fully integrated microreactors.