The use of enzymes in industrial or medical applications has been limited (except for proteases and some amylases) because most enzymes are relatively unstable and the cost of their isolation and purification is still high. In addition, it is technically very expensive to recover active enzyme from the reaction mixture at the end of a process when enzyme is used free in the bulk. Since the pioneering work of Katchalski and coworkers, enzyme immobilization on various carriers has been developed, and over the past two decades the number of methods available for this purpose has increased significantly (1 ).
