title: Immobilization on chitosan of a thermophilic beta-glycosidase expressed in Saccharomyces cerevisiae.
abstract: A Sulfolobus solfataricus beta-glycosidase expressed in Saccharomyces cerevisiae (S beta gly) was immobilized on chitosan activated with glutaraldehyde. The yield of immobilization was evaluated as 80%. Compared to the free beta-glycosidase, the immobilized enzyme showed a similar pH optimum (pH = 7.0), the same increasing activity up to 80 degrees C, improved thermostability, and no inhibition by glucose. Functional studies pointed out that the kinetic constant values for both enzymes were comparable. A bioreactor, assembled with the immobilized S beta gly, was used for glucose production. The values of cellobiose conversion increased on increasing residence time in the bioreactor, following a nonlinear trend. However, the highest glucose production/min was obtained at a flow of 0.5 mL/min.
authors.affiliation: Istituto di Biochimica delle Proteine ed Enzimologia, C. N. R., Naples, Italy.
authors.forename: S
authors.initials: S
authors.lastname: D'Auria
authors.forename: F
authors.initials: F
authors.lastname: Pellino
authors.forename: F
authors.initials: F
authors.lastname: La Cara
authors.forename: R
authors.initials: R
authors.lastname: Barone
authors.forename: M
authors.initials: M
authors.lastname: Rossi
authors.forename: R
authors.initials: R
authors.lastname: Nucci
mesh_terms: D002686:Chitin / Q000031:analogs & derivatives*; D048271:Chitosan; D004795:Enzyme Stability; D004800:Enzymes, Immobilized; D005959:Glucosidases / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D012441:Saccharomyces cerevisiae; D013696:Temperature
chemical_list: D004800:Enzymes, Immobilized; D002686:Chitin; D048271:Chitosan; D005959:Glucosidases; C104851:Sulfolobus solfataricus beta-glycosidase