Immobilization of enzymes on supports is a valuable technique for increasing total productivity and life-span of biocatalysts. Conventionally, enzymes are immobilized on water-insoluble supports, such as polysaccharide derivatives, ion exchange resin, and so on. However, in a heterogeneous reaction system involving solid substrate and/or reactant, the enzyme immobilized on such supports can cause problems of substrate diffusion within the support (1 ), enzyme leakage from the support (2 ,3 ), and separation of the immobilized enzyme from unreacted solid residue and/or solid reactant in the reaction mixture (seeChapter 1 ) (5 ).
