Preparation and Characterization of Enzyme Compartments in UV-Cured Polyurethane-Based Materials and Their Application in Enzymatic Reactions

Abstract

The preparation and characterization of UV-cured polyurethane-based materials for the mild inclusion immobilization of enzymes was investigated. Full curing of the polymer precursor/enzyme solution mixture was realized by a short irradiation with UV-light at ambient temperatures. The included aqueous enzyme solution remains highly dispersed in the polymer material with an even size distribution throughout the polymer material. The presented concept provides stable enzyme compartments which were applied for an alcohol dehydrogenase-catalyzed reduction reaction in organic solvents. Cofactor regeneration was achieved by a substrate-coupled approach via 2-propanol or an enzyme-coupled approach by a glucose dehydrogenase. This reaction concept can also be used for a simultaneous application of contrary biocatalytic reaction conditions within an enzymatic cascade reaction. Independent polymer-based reaction compartments were provided for two incompatible enzymatic reaction systems (alcohol dehydrogenase and hydroxynitrile lyase), while the relevant reactants diffuse between the applied compartments.

Kompartimentierung bei den Enzymkaskaden: statisch oder Durchfluss

“…Die Darstellung erfolgt entweder mit einer vorgeformten Polymerhülle, welche dann mit dem Biokatalysator befüllt wird, oder durch Bildung einer temporären Emulsion aus dem hydrophoben Präpolymer und der wässrigen Lösung mit einer anschließenden Wärmeoder UV-Licht-induzierten Aushärtung. Ein Beispiel sind Reaktionskaskaden mit einer Alkoholdehydrogenase-Hydroxynitrillyase-Kombination in separierten Reaktionsräumen [8]: Hier verbleiben die Biokatalysatoren in separierten Reaktionsräumen mit den jeweiligen optimalen Reaktionsbedingungen, während die Reaktanden frei zwischen den Kompartimenten diffundieren. Das Konzept fi ndet darüber hinaus Anwendung in chemoenzymatischen Reaktionen, z.…”

Application of In Situ Product Crystallization and Related Techniques in Biocatalytic Processes

“…introduced compartmentalized chemoenzymatic cascade reactions, which included bio‐ and organocatalysis . Similarly, enzymatic reaction systems with differing reaction specifications can be used to gain higher conversions . Recently, polymersomes, which are composed of amphiphilic self‐assembling molecules (similar to membrane vesicles), attracted interest for their use as nanoreactors …”

Biotransformations in Pure Organic Medium: Organic Solvent‐Labile Enzymes in the Batch and Flow Synthesis of Nitriles

“…[15,23] Encapsulation of whole cells in polyurethanes, as shown by von Langermann et al, turned out as a highly suitable technique to prevent contact of the biocatalyst with the organic medium, thus resulting in a significant higher stability of the catalyst in such me-dia. [23,26] In continuation of our ongoing study on the use of enzymes being immobilized in superabsorber materials as a technique for immobilization of "free" enzymes, [22,27,28] and our research work on aldoxime dehydratase and their application for the synthesis of nitrile bulk chemicals in the presence of aldoxime dehydratases, [29][30][31] we became interested if such superabsorber-immobilized whole cell catalysts can be successfully used in pure organic medium. In the following we report the development of such a solution for utilizing whole-cell catalysts being immobilized in superabsorbers in pure organic media, which also provides the perspective for a broad general applicability in biocatalysis.…”

“…In case of whole cell immobilization, , , some methods showed stabilizing effects and biocatalysts were found to be more stable in presence of organic solvents , . Encapsulation of whole cells in polyurethanes, as shown by von Langermann et al ., turned out as a highly suitable technique to prevent contact of the biocatalyst with the organic medium, thus resulting in a significant higher stability of the catalyst in such media , . In continuation of our ongoing study on the use of enzymes being immobilized in superabsorber materials as a technique for immobilization of “free” enzymes,, , and our research work on aldoxime dehydratase and their application for the synthesis of nitrile bulk chemicals in the presence of aldoxime dehydratases, we became interested if such superabsorber‐immobilized whole cell catalysts can be successfully used in pure organic medium.…”