Authors: Mohammad Jahir Khan Qayyum Husain Ameer Azam
Publish Date: 2012/04/03
Volume: 17, Issue: 2, Pages: 377-384
Abstract
Enzymes play a pivotal role in catalyzing diverse reactions However their instability upon repetitive/prolonged use as well as their inhibition by high substrates and product concentration remains an area of concern In this study porcine pancreatic αamylase was immobilized on magnetic Fe2O3 nanoparticles Fe2O3NPs in order to hydrolyze starch The magnetic nanoparticle bound enzymes retained 94 of their initial enzyme activity Xray diffraction and atomic force microscopy analyses showed that the prepared matrix had advantageous microenvironment and a large surface area for binding significant amounts of protein Functional groups present in enzyme and support were monitored by Fourier transform infrared spectroscopy Immobilized enzyme exhibited lowered pH optimum pH 60 to a greater degree than its soluble counterpart pH 70 Optimum temperature for the immobilized enzyme shifted towards higher temperatures The immobilized enzyme was significantly more resistant to inactivation caused by various metal ions and chemical denaturants Immobilized αamylase hydrolyzed 92 starch in a batch process after 8 h at 40°C while the free enzyme could hydrolyze only 73 starch under similar experimental conditions A reusability experiment demonstrated that the immobilized enzyme retained 83 of its original activity even after its 8th repeated use
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