Continuous Production of Glucose from Dextrin by Glucoamylase Immobilized on Porous Silica,

摘要

Glucoamylase was covalently attached to porous silica particles and investigated for its applicability as an industrial catalyst in the production of glucose from starch hydrolysates. Reactivity at various reaction conditions,as well as enzyme loading,reaction kinetics,diffusional effects,and thermal stability,were determined in laboratory scale experiments. Pilot scale tests on continuous production of a glucose were performed in a 1cubic foot packed column reactor that could produce approximately 1,000lbs/day glucose at 40degrees C. The maximum glucose concentration (based on dissolved solids) varied from 87to 93percent depending on the dextrose equivalent (D.E.) and degree of retrogradation of the feed dextrin. In 80days of continuous operation no appreciable enzyme deactivation was observed. Initial sterilization of the reactor and continuous heat sterilization of the feed stream (120degrees C, 3-4min) virtually ensured operation of the immobilized enzyme reactor at low levels of contamination,typical bacteria counts of the product effluent being 30-50/ml.