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

生物催化合成epsilon-己内酯（ECL）及其低聚物/聚合物与化学方法相比具有资源效率、选择性、环境和安全性等重要优势，因此备受关注。本文介绍了一种由乙醇脱氢酶（ADH）和Baeyer-Villiger单加氧酶（BVMO）组成的双酶系统合成ECL的新型氧化还原-中性聚合级联反应。在初步研究中确定的主要限制之一是由于ECL积累而产生的产物抑制和酶失活，因此必须将其从反应介质中去除。该研究项目旨在开发一种合理的方法，在会聚BVMO-ADH级联系统中高效合成ECL，并结合有效的原位开环聚合（ROP）来提高ECL的酶学性能。同时，低聚物/聚合物产品将被合成，从而减少由分离和净化步骤产生的废物。为了实现这些目标，将系统地描述和定量评估影响ECL及其低聚物/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。为了有效地设计多酶级联反应，需要建立一个描述系统动力学的可靠模型。总的来说，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可观的潜力。这里提出的研究将建立一种高效、环保的ECL及其聚合物/低聚物的合成方法，这将减轻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.