Processes with immobilized enzymes and cells

The immobilization of enzymes is a technique extensively studied since the late 1960s (Silman and Katchalski, 1966). The knowledge base accumulated on enzyme and cells immobilization studies has grown to very large proportions (Klibanov, 1983; Ariga et al., 1993; Crumbliss et al., 1993; Champagne et al., 1994). This wealth of information is one of the primary reasons for the present advances in enzyme engineering. The introduction of immobilized enzyme systems into commercial use, which was slower than predicted, has been the result of numerous factors, such as the long time required for approval of new processes for use in food applications, the need to control microbial contamination in biological reactor systems and some enzyme characteristics that limit the economic success of the immobilization process. The engineering of enzymes with better characteristics will overcome some of the problems encountered that have prevented commercial processes from developing.