Immobilization of Enzymes for Use in Organic Media

When enzymes are to be used in organic media, noncovalent immobilization methods are often used because enzymes in general are insoluble in those media. Usually, immobi-lization increases the observed catalytic activity drastically as compared with nonimmobilized enzyme powder. The main reason is that immobilization spreads the enzyme on a relatively large area, which facilitates the mass transfer of substrates and products. The morphology of the support material is thus of crucial importance. In many applications, a monolayer of enzyme on the support provides catalysts with good activity. In general, the enzyme is first present in an aqueous solution and water is then removed using a drying procedure. Simple and effective methods for the adsorption of lipase on porous polypropylene and deposition of a -chymotrypsin on Celite � are presented in this chapter.