Production of maltose and maltotriose from starch and pullulan by a immobilized multienzyme of pullulanase and β‐amylase

Abstract Pullulanase was immobilized on tannic acid and TEAE‐cellulose, and β‐amylase was covalently immobilized on p‐aminobenzylcellulose. Both the immobilized enzymes showed similar properties in pH and temperature optima and heat stability. On passing the pullulan solution at high temperature (50°C) through a column packed with immobilized pullulanase, only maltotriose was obtained for ten days and the half‐life was about 15 days. In a continuous reaction using immobilized multienzyme, starch was completely converted into maltose at 50°C and at a space velocity of 1.2, a comparative longer half‐life (20 days) was obtained. It was concluded that starch was smoothly converted into maltose with the aid of α‐amylase contaminated in the immobilized pullulanase and the operational stability of the column increased with 2‐5mM Ca2+.