"By enabling efficient enzyme recovery, this microgel system overcomes significant obstacles in using natural enzymes in laboratory and industrial settings," said Bruce Armitage, associate professor of chemistry at Carnegie Mellon, who developed the recoverable enzymatic microgel in collaboration with chemistry professor Gary Patterson, and graduate students Rong Cao and Zhenyu Gu.
Enzymes are routinely used in manufacturing to catalyze important reactions, such as the breakdown of sugars to create lactose-free milk or cheese products for the dairy industry. In many cases, industrial enzymes are embedded in a solid, synthetic matrix to easily separate them from their chemical product after a reaction takes place. But embedded enzymes may eventually leach from a matrix. The chemical cross-linking reaction used to attach the enzymes to the matrix also can inadvertently inactivate the enzymes, rendering them useless. What's more, large chemicals cannot enter a dense matrix to react with embedded enzymes.
The microgel developed by Armitage and Patterson bypasses these limitations. The enzyme is tightly connected to the microgel matrix, but remains fully functional. Molecules can diffuse into the porous microgel and undergo chemical reaction when they encounter an enzyme. The product can then diffuse out of the microgel. Separation of the product from the enzyme takes advantage of the fact that the microgel particles precipitate from solution at a low temperature. After the product has been removed, the microgel particles can be re-suspended by adding fresh water and heating the solution.