(582ad) Enzymatic Cascade Reactions for Synthesis of High Value Products in a Multiphase System

The production of high value products is still a growing market in the field of white biotechnology. Due to the demand on high selectivity and purity of products, enzymatic cascade reactions have a quite high potential. Usually in-vivo systems are used, although they have a low time-space yield, are quite complex and hard to describe and optimize mathematically. In addition, a lot of by-products are formed. In-vitro systems with isolated enzymes are contrary: less by-products, less complex, easy to optimize. However, a big drawback is the lack of co-factor regeneration. In this study we describe an enzymatic cascade reaction system with integrated co-factor regeneration within the total synthesis pathway.

By the example of high value products derived from natural educts a cascade reactor system is presented and described. Because the co-factor depending dehydrogenases are only active in water and the natural educts are organic, a multiphase system has to be set up. In addition an in-situ product removal is strived to enhance the total conversion and realize a continuous process. The individual reactions and unit operations are modeled and aggregated to a complex system.

An alcohol dehydrogenase and an aldehyde dehydrogenase are used. While one enzyme needs NAD as co-factor and NADH is produced, the other enzyme needs NADH producing NAD. In addition a lipase is used within the reaction pathway to synthesize high value products. As model reactants organic acids, alcohols, aldehydes and esters are used which are relevant as flavors and fragrances.

This presentation outlines the whole production process and gives first experimental results of single unit operations. This decomposition offers the opportunity for a structured analysis of the complete process.