ERA-Chemistry - Enzymatic Carboxylation in Ionic Liquids

使用碳酸氢盐作为二氧化碳源，通过各种脱羧酶催化芳烃的酶促羧化反应，是一种非常有前途的生物合成工具，是传统化学（Kolbe-Schmitt）方法的“绿色”替代品，通常需要苛刻的反应条件。尽管可用的酶具有完美的区域选择性，但在热力学上不利于实现所需的生物合成羧基化，因此受到不完全转化的阻碍，这是该项目中最艰巨的挑战之一。工程的生物催化过程使用新的工具，以原位产物去除反应萃取以及离子液体的使用将进行研究。此外，两个酶反应的级联系统，其中产物I是酶II的底物将被评估。总的来说，这些战略的目的是将均衡转变为完全转换。本提案的进一步主要研究重点将是生物催化剂的工程设计和候选酶的底物范围评估，包括突变体，因为后者对于生物催化方法在工业应用中至关重要。

The enzymatic carboxylation of aromatics catalysed by various decarboxylases, using bicarbonate as CO2 source, represents a very promising biosynthetic tool as 'green' alternative to classic chemical (Kolbe-Schmitt) methods which often require harsh reaction conditions. Despite the perfect regio-selectivity of the available enzymes, the direction towards desired biosynthetic carboxylation is thermodynamically disfavored and therefore impeded by incomplete conversion, which represents one of the most demanding challenges within this project. Engineering of the biocatalytic process using novel tools for in-situ product removal by reactive extraction as well as the use of ionic liquids will be investigated. Furthermore, a cascade systems of two enzymatic reaction in which product I is the substrate of enzyme II will be evaluated. Overall, these strategies aim at the shift of the equilibrium towards full conversion. A further main research focus of this proposal will be the engineering of the biocatalysts and the evaluation of the substrate scope of the enzyme candidates including mutants since the latter is of crucial importance for a biocatalytic approach in view of industrial application.