Immobilization of Aspergillus beta-glucosidase on chitosan.
beta-Glucosidase of Aspergillus phoenicis QM 329 was immobilized on chitosan, using the bifunctional agent glutaraldehyde. The most active preparation based on the amount of support contained a 1:2.5 enzyme-to-chitosan ratio (wt/wt). However, the specific activity of the bound enzyme decreased from 10 to 1% with increasing enzyme-to-chitosan ratio. Compared with free beta-glucosidase, the immobilized enzyme exhibited: (i) a similar pH optimum but more activity at lower pH values; (ii) improved thermal stability; (iii) a similar response to inhibition by glucose; and (iv) mass transfer limitations as reflected by higher apparent Km and lower energy of activation.
D001230:Aspergillus / Q000201:enzymology*; D004187:Disaccharides / Q000378:metabolism; D004800:Enzymes, Immobilized / Q000378:metabolism; D005944:Glucosamine; D005947:Glucose / Q000494:pharmacology; D005959:Glucosidases / Q000378:metabolism; D005976:Glutaral; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D011134:Polysaccharides; D013379:Substrate Specificity; D013696:Temperature; D001617:beta-Glucosidase / Q000378:metabolism
D004187:Disaccharides; D004800:Enzymes, Immobilized; D011134:Polysaccharides; D005959:Glucosidases; D001617:beta-Glucosidase; D005947:Glucose; D005944:Glucosamine; D005976:Glutaral