Directed evolution produces enzyme suitable for carbon capture

Ars Technica : One process developed to capture the carbon dioxide emitted by power plants generally uses amines to separate the CO₂ molecules from the other gases being released. Certain amine solutions require high temperatures to work effectively. Because they use some of the plant’s generated heat, the amount of heat available to generate electricity is reduced, and so is the plant’s efficiency. Others amines can work at lower temperatures, but are so slow that the amount of CO₂ that they trap is reduced. Industry researchers wanted to combine the lower temperature amines with carbonic anhydrase, an enzyme many organisms use for the fast transport of CO₂. However, the enzyme does not function well in hot and acidic conditions, such as those found in coal power plants. Now a group of researchers has shown that it is possible to customize the enzyme via controlled mutations to make it resistant to those conditions. By artificially selecting versions of the enzyme that showed increased resistance, they were able to significantly increase the effectiveness of the enzyme even under extreme conditions. When the modified enzyme was introduced to the slow amine solution, it captured carbon 25 times faster.