this research is devoted to the enzymatic methods of making fructose, a subject of current industrial interest. a wide variety of methods of immobilization of the enzyme have been screened, including containing it in heat-activated cells ('whole' cells), trapping in cellulose acetates, adsorbing on deae cellulose, and covalent bonding to agarose, controlled-pore glass, and cellulose. the authors devised several ways of improving the activity of enzymic preparations trapped in cellulose acetate. the effects of several important variables on the performance of reactors containing immobilized enzymes were measured, industrial-scale reactors were designed, and the variables of design and operation were optimized. also important to this project is the development of methods of using oxidoreductases, methods capable of being used industrially. several methods of immobilization of the enzyme were screened, including trapping in polyacrylamide, containment in hollow fibers, and covalent bonding to controlled-pore glass and sand. several aspects of the problem of devising economical ways of using the cofactor were studied. thirty thousand reuses of the cofactor were obtained by conducting a simultaneous reverse reaction in the same reactor, thus providing in-place regeneration