可用于二氧化碳捕获过程的微生物碳酸酐酶的挖掘与改造

Mining and engineering of microbial carbonic anhydrases for biomimetic carbon dioxide sequestration

摘要:

二氧化碳排放量的急剧上升引起全球温室效应加剧。碳酸酐酶是地球上反应速率最快的几种酶之一，可以大幅提高CO2捕获和生物矿化的效率，从而降低大气中CO2的排放量。但捕获过程在高温条件，而CO2生物矿化形成CaCO3的过程则需要碱性条件。因此，迫切需要筛选出既嗜热又耐碱的碳酸酐酶以用于CO2捕获，极端微生物是这类酶的重要来源之一。文中系统、深入地介绍了目前从极端微生物或利用蛋白质工程技术获取嗜热、耐碱的碳酸酐酶的最新研究进展，同时简要介绍了一些新型固定化碳酸酐酶的方法。最后指出当前研究的重点应致力于拓宽寻找碳酸酐酶的范围，改良蛋白质工程改造技术，研发高效廉价、易于放大的固定化方法，为减轻温室效应、延缓全球变暖这一迫切需要解决的问题提供新思路。

Abstract:

The increasing atmospheric carbon dioxide levels have been correlated with global warming. Carbonic anhydrases (CA) are the fastest among the known enzymes to improve carbon capture. The capture of carbon dioxide needs high temperature and alkaline condition, which is necessary for CaCO3 precipitation in the mineralization process. In order to use CAs for biomimetic carbon sequestration, thermo-alkali-stable CAs are, therefore, essential, and polyextremophilic microbes are one of the important sources of these enzymes. The current review focuses on both those isolated by thermophilic organisms from the extreme environments and those obtained by protein engineering techniques, and the industrial application of the immobilized CAs is also briefly addressed. To reduce the greenhouse effect and delay global warming, we think further research efforts should be devoted to broadening the scope of searching for carbonic anhydrase, modifying the technology of protein engineering and developing highly efficient immobilization strategies.