title: Calcium alginate entrapped preparation of α-galactosidase: its stability and application in hydrolysis of soymilk galactooligosaccharides.
abstract: Thermostable α-galactosidase from Aspergillus terreus (GR) was insolubilized using concanavalin A obtained from jack bean extract and in order to maintain the integrity of complex in the presence of its substrate or products, this complex was crosslinked with glutaraldehyde. Soluble α-galactosidase entrapped in calcium alginate retained 82% of enzyme activity whereas, Con A-α-galactosidase complex entrapped in calcium alginate and crosslinked Con A-α-galactosidase complex entrapped calcium alginate retained 74 and 61% activity, respectively. A fluidized bed reactor was constructed for continuous hydrolysis of galactooligosaccharides in soymilk using crosslinked Con A-α-galactosidase complex entrapped calcium alginate. Optimum conditions such as pH (5.0) and temperature (65°C) were the same for all immobilized enzyme preparations and soluble enzyme. Crosslinked Con A-α-galactosidase entrapped complex exhibited enhanced thermostability and showed 62% of activity (38%) after 360 min at 65°C. Entrapped crosslinked Con A-α-galactosidase complex preparation was superior in the continuous hydrolysis of oligosaccharides in soymilk by batch processes compared to the other entrapped preparations. The entrapped crosslinked concanavalin A-α-galactosidase complex retained 95% activity after eight cycles of use.
authors.affiliation: Department of Biochemistry, Gulbarga University, Gulbarga, 585106, Karnataka, India.
authors.forename: S K
authors.initials: SK
authors.lastname: Shankar
authors.forename: S K Praveen
authors.initials: SK
authors.lastname: Kumar
authors.forename: V H
authors.initials: VH
authors.lastname: Mulimani
mesh_terms: D000464:Alginates / Q000737:chemistry*; D001230:Aspergillus / Q000201:enzymology; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000378:metabolism*; D005690:Galactose / Q000378:metabolism; D020723:Glucuronic Acid / Q000737:chemistry; D005976:Glutaral / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D009844:Oligosaccharides / Q000737:chemistry / Q000378:metabolism*; D041942:Soy Milk / Q000737:chemistry*; D013696:Temperature; D000519:alpha-Galactosidase / Q000378:metabolism*
chemical_list: D000464:Alginates; D004800:Enzymes, Immobilized; D006603:Hexuronic Acids; D009844:Oligosaccharides; D020723:Glucuronic Acid; D000519:alpha-Galactosidase; D005976:Glutaral; D005690:Galactose