Dariush Saberi

Immobilization of -amylase was carried out by ionic exchange and hydrophobic interactions on goldnanorods (GNRs) synthesized via sequential seed mediated growth method. The optimum temperature of -amylase increased from 50 to 60?C and its optimum pH was shifted from 6 to 7 upon immobilization.The kinetic parameters, Km and Vmax values were 3 mg/ml and 6.4 m min?1for free and 3.4 mg/ml and 5.91 m min?1for immobilized enzymes, respectively. The immobilization process brought significantenhancement of stability to temperature and extreme pH values with respect to free -amylase. Enzymeshows higher functionality than the free form when incubated for long time (1 h) at 80?C and at extremepH values (3 and 10). In addition to improving thermal stability, the storage stability of -amylse exhibiteda significant increase upon immobilization which makes it a biocatalyst of possible industrial application,specially a potential candidate for production of glucose syrups on industrial scale.