Characterisation and kinetic modelling of a novel convergent enzymatic cascade for epsilon-caprolactone synthesis employing a double-smart cosubstrate with in situ polymerisation

己内酯(ECL)及其齐聚物的生物催化合成因其在资源效率、选择性、环境和安全性等方面较化学方法具有重要的优势而备受关注。在乙醇脱氢酶(ADH)和Baeyer-Villiger单加氧酶(BVMO)组成的双酶体系中，最近提出了一种用于合成ECL的新型氧化还原中性收敛级联反应。初步研究中确定的主要限制之一是ECL积累导致的产物抑制和酶失活，因此有必要将其从反应介质中移除。该研究项目旨在开发一种在收敛的BVMO-ADH级联体系中高效合成ECL的合理方法，并结合有效的ECL的原位开环聚合(ROP)以提高酶性能。同时，低聚物/聚合物产品将被合成，从而减少分离和纯化步骤产生的废物。为实现这些目标，将对影响ECL及其齐聚物/聚合物产品合成效率的关键反应参数、动力学和热力学效应进行系统描述和定量评估。为了有效地设计多酶链式反应，需要建立一个可靠的模型来描述系统的动力学。总体而言，拟议的方法尚未得到调查，它代表了一种独特的方法，对未来的发展研究具有绝对相当大的潜力。本文介绍的研究将建立一种高效和环境友好的ECL及其聚合物/低聚物的合成方法，这将缓解目前化学方法中观察到的严重缺陷。

Biocatalytic synthesis of epsilon-caprolactone (ECL) and oligomers/polymers thereof is of high interest owing to important advantages compared to chemical approach concerning resource efficiency, selectivity, environment and safety. A novel redox-neutral convergent cascade for the synthesis of ECL in a bi-enzymatic system consisting of an alcohol dehydrogenase (ADH) and a Baeyer-Villiger monooxygenase (BVMO) has been recently introduced. One of the main limitations identified in the preliminary studies was the product inhibition and enzyme deactivation owing to ECL accumulation, and hence its removal from the reaction medium becomes necessary. The research project aims at the development of a rational approach for highly productive synthesis of ECL in convergent BVMO-ADH cascade system coupled with an effective in situ Ring-Opening-Polymerisation (ROP) of ECL for enhancing enzymatic performances. At the same time, oligomer/polymer products will be synthesised and hence the waste generated by separation and purification steps will be reduced. To achieve these goals, key reaction parameters, kinetic and thermodynamic effects influencing the productivity in the synthesis of ECL and its oligomer/polymer products will be systematically described and quantitatively evaluated. The development of a reliable model describing the kinetics of the system is required for the effective design of the multi-enzymatic cascade. Overall, the proposed approach has not been investigated yet and it represents a unique approach, which possess an absolutely considerable potential for future development studies. The research presented here will establish a highly efficient and environmentally benign synthesis of ECL and polymers/oligomers thereof, which will alleviate the severe drawbacks observed in the current chemical approach.