CO2生物转化关键酶固定体系构筑研究进展与挑战

Development of enzyme immobilization systems for CO2 bioconversion: advances and challenges

摘要:

酶催化CO₂还原制备高值化学品对缓解全球环境和能源危机具有重要意义，利用甲酸脱氢酶(formate dehydrogenase,FDH)或多酶级联还原CO₂制备甲酸/甲醇具有选择性高、条件温和的优势，但关键酶活性低、稳定性差和重复利用率低的问题限制了其规模化应用，酶的固定化为这些问题提供了有效解决方案。本文总结了近年来利用膜、无机材料、金属有机框架和共价有机框架等载体对酶进行固定化的研究进展，阐释了不同固定材料和固定方式的特点和优势；进一步总结了固定化酶与电催化或光催化耦联反应体系对CO₂还原的协同效果及应用，同时指出酶固定化技术和耦联反应体系目前存在的问题并对其发展前景进行了展望。

Abstract:

Enzyme-catalyzed CO₂ reduction to value-added commodities is important for alleviating the global environmental issues and energy crises due to high selectivity and mild conditions. Owing to high energy density, formic acid or methanol produced from CO₂ using formate dehydrogenase (FDH) or multi-enzyme cascades are promising target chemicals for CO₂ utilization. However, the low activity, poor stability and low reusability of key enzymes involved in such process hampered its large-scale application. Enzyme immobilization provides an effective solution to these problems and significant progress have been made in immobilization carriers. Moreover, integration of enzyme immobilization with other catalysis techniques have been explored extensively. This review summarized the recent advances in the immobilization of enzymes using membranes, inorganic materials, metal-organic frameworks, covalent organic frameworks and other carriers, and illustrated the characteristics and advantages of different immobilization materials and immobilization methods. The synergistic effects and applications of immobilized enzymes and electrocatalytic or photocatalytic coupling reaction systems for CO₂ reduction were further summarized. Finally, the current challenges of enzyme immobilization technology and coupling reaction systems were pointed out and their development prospects were presented.