Immobilization of B. amyloliquefaciens α-amylase and comparison of some of its enzymatic properties with the free form

Abstract

The enzyme alpha-Amylase from Bacillus amyloliquefaciens was entrapped by drop-wise addition of an aqueous mixture of sodium alginate in the solution of a Ca2+ salt. Effects of immobilization conditions were investigated. Optimum alginate and CaCl2 concentrations were found to be 2% and 5% (w/v), respectively. The immobilization yield was 89%. Amylase activity increased with increasing enzyme loading on the beads. The best size and amount of beads for achieving enzyme activity were found to be 3 mm and 0.4 g, respectively. When coated with silicate, amylase-entrapped beads retained the highest catalytic activity. The highest operational stability was six reuses with 51% residual activity. Some properties of immobilized enzyme were determined, and compared with those of free enzyme. Product profile of the various raw starches has been determined by thin layer chromatography.