期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2014
卷号：111
期号：46
页码：16436-16441
DOI：10.1073/pnas.1411461111
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：SignificanceIt is clear that to address climate change, the amount of CO2 released into the atmosphere by industrial processes has to be reduced. Carbonic anhydrase regulates CO2 in nearly every single living organism and is one of the most efficient enzymes in nature. To leverage that efficiency, a {beta}-class carbonic anhydrase was engineered using directed evolution to withstand some of the harshest conditions associated with an industrial carbon capture process. The approach laid out can be generally applied in the development of natural enzymes for their use in industrial applications. Carbonic anhydrase (CA) is one of nature's fastest enzymes and can dramatically improve the economics of carbon capture under demanding environments such as coal-fired power plants. The use of CA to accelerate carbon capture is limited by the enzyme's sensitivity to the harsh process conditions. Using directed evolution, the properties of a {beta}-class CA from Desulfovibrio vulgaris were dramatically enhanced. Iterative rounds of library design, library generation, and high-throughput screening identified highly stable CA variants that tolerate temperatures of up to 107 {degrees}C in the presence of 4.2 M alkaline amine solvent at pH >10.0. This increase in thermostability and alkali tolerance translates to a 4,000,000-fold improvement over the natural enzyme. At pilot scale, the evolved catalyst enhanced the rate of CO2 absorption 25-fold compared with the noncatalyzed reaction.
