Open AccessEFFECTS OF DIFFUSION ON THE KINETICS OF MALTOSE HYDROLYSIS USING GLUCOAMYLASE IMMOBILIZED ON MACROPOROUS SILICA
Author(s) -
Leandra Regina Gonçalves,
Raquel de Lima Camargo Giordano
Publication year - 1997
Publication title -
brazilian journal of chemical engineering/brazilian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.313
H-Index - 52
eISSN - 1678-4383
pISSN - 0104-6632
DOI - 10.1590/s0104-66321997000400007
Subject(s) - maltose , glutaraldehyde , chemistry , hydrolysis , chromatography , immobilized enzyme , dextrin , diffusion , kinetics , mass transfer , product inhibition , enzyme kinetics , enzyme , chemical engineering , organic chemistry , thermodynamics , non competitive inhibition , active site , physics , quantum mechanics , starch , engineering
In this work the effects of diffusion on the hydrolysis of maltose using glucoamylase immobilized on macroporous silica at 30o C are studied. Two different kinds of experimental assays are carried out: one using free enzyme and the other using an enzyme covalently linked to macroporous silica, preactivated with glutaraldehyde. Free enzyme assays are used to estimate the kinetic parameters for hydrolysis of maltose at 30ºC, according to a Michaelis-Menten equation, with inhibition by the product. Runs with the immobilized enzyme enable us to estimate dextrin diffusivities in silica, assuming that the inherent kinetic parameters are equal to the intrinsic ones. The values of kinetic and mass transfer parameters are: K3 = 0.90x10-5 g/U.s, Km = 0.61x10-3 g/ml, Ki = 1.23x10-1 g/ml, DMs = 0.50x10-6 cm2 /s and DGs = 0.55x10-6 cm2 /