Immobilization of invertase attached to a granular dimer acid-co-alkyl polyamine

Invertase was immobilized onto the granular dimer acid-co-alkyl polyamine a fter activation with carbodiimide. The K-m value for immobilized enzyme (53 .6 mM) was much greater than that of the free enzyme (20.6 mM). V-max value s were 6.44x10(-5) mol dm(-3) min(-1) and 5.45x10(-5) mol dm(-3) min(-1) fo r free and bound, respectively. The optimal pH values for free and covalent ly bonded enzymes were 4.56 and 5.50, respectively. The optimum temperature for both free and covalent invertase was 55 degrees C. The enzyme activiti es, after storage for 1 month, were found to be 21.0 and 99.0% of the initi al activity values for free and covalently bonded, respectively. The immobi lized enzyme that was used 50 times in 5 days in repeated batch experiments showed 100% of its original activity. (C) 2000 Elsevier Science Ltd. All r ights reserved.