Table of Contents
International Scholarly Research Notices
Volume 2014 (2014), Article ID 936129, 8 pages
Research Article

Entrapment of -Amylase in Agar Beads for Biocatalysis of Macromolecular Substrate

1Department of Pharmacy, Banasthali University, Bansthali 304022, India
2Department of Bioscience and Biotechnology, Banasthali University, Bansthali 304022, India
3Department of Pharmaceutics, Delhi Institute of Pharmaceutical Sciences and Research, Formerly College of Pharmacy, University of Delhi Pushp Vihar, Sector III, New Delhi 110017, India

Received 17 April 2014; Accepted 28 June 2014; Published 15 September 2014

Academic Editor: Giuseppe Maurizio Campo

Copyright © 2014 Manu Sharma et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Attempts have been made to optimize immobilization parameters, catalytic property, and stability of immobilized α-amylase in agar. The work compares natural entrapment efficiency of agar with the ionotropically cross-linked agar hydrogel, with the advantage of easy scale-up and cost and time effectiveness. Beads prepared with 3% (w/v) agar and 75 mM calcium chloride and hardened for 20 minutes were selected for further studies on the basis of entrapment efficiency (80%) and physical stability. Following entrapment, pH and temperature optima of enzyme were shifted from 6 to 6.5 and 50 to 55°C, respectively. Michaelis constant () for both free and entrapped enzymes remained the same (0.83%) suggesting no change in substrate affinity. However, of entrapped enzyme decreased ~37.5-fold. The midpoint of thermal inactivation for entrapped enzyme increased by 8 ± 1°C implying its higher thermal stability. The entrapped enzyme in calcium agar bead had an Ea value of 27.49 kcal/mol compared to 17.6 kcal/mol for free enzyme indicating increased stability on entrapment. Half-life of enzyme increased ~2.2 times after entrapment in calcium agar at 60°C indicating stabilization of enzyme. The reusability of beads was size dependent. Beads with diameter <710 μm were stable and could be reused for 6 cycles with ~22% loss in activity.