A MODEL STUDY ON EUDRAGIT AND POLYETHYLENEIMINE AS SOLUBLE CARRIERS OF ALPHA-AMYLASE FOR REPEATED HYDROLYSIS OF STARCH

Eudragit and poIyethyleneimine have been evaluated for their potential as soluble carriers of enzymes acting on macromolecular substrates. The present study is based on coupling of alpha-amylase (Termamyl) to these polymers for the degradation of starch. The enzyme was bound to both the polymers by carbodiimide coupling. Using soluble starch as substrate, about 96% of the enzyme activity was found to be retained on binding to Eudragit, while the binding to polyethyleneimine resulted in activation of the enzyme. Kinetic properties and optimal conditions for activity and stability of the soluble-immobilized enzyme preparations were compared with that of the free enzyme. The polymer-enzyme complexes were also used for the repeated hydrolysis of starch, the biocatalyst being recovered in between runs by precipitation. The enzyme in the immobilized form exhibited good stability during repeated runs of starch liquefaction.