%0 Journal Article
%T Caracteriza£¿£¿o cin¨¦tica e termodinamica de ¦Â-galactosidase de Kluyveromyces marxianus CCT 7082 fracionada com sulfato de am£¿nio
%A Heidtmann
%A Renata Bemvenuti
%A Duarte
%A Susan Hartwig
%A Pereira
%A Lidiane Pereira de
%A Braga
%A Anna Rafaela Cavalcante
%A Kalil
%A Susana Juliano
%J Brazilian Journal of Food Technology
%D 2012
%I Instituto de Tecnologia de Alimentos - ITAL
%R 10.1590/S1981-67232012000100005
%X ¦Â-galactosidase is an important enzyme that acts on lactose hydrolysis and can be used to obtain food for consumers intolerant to this disaccharide. the yeast kluyveromyces marxianus presents a good growth yield, is a safe microorganism for industrial applications and has been used for enzyme production using the submerged process. the ¦Â-galactosidase obtained was fractionated with ammonium sulphate and characterized with respect to its optimum temperature and ph, thermal stability and its d and z values, as well as its kinetic and thermodynamic parameters. the optimum temperature and ph were 45-50 ¡ãc and 7.0, respectively. the activation energy and the deactivation reaction of the enzymatic reaction were, respectively, 9.8 kcal.mol-1 and 64.2 kcal.mol-1. the km and vmax values obtained were 3.7 mm and 99.0 u.ml-1, respectively. the gibbs free energy decreased with increasing temperature and the enzyme was more stable at 30 ¡ãc (£¿g* = 106.8 kj.mol-1). the enthalpy was 313.04 kj.mol-1 and entropy 0.68 kj.mol.k-1. the d value confirmed that the enzyme was more stable at temperatures around 30 ¡ãc (d = 11,513.0 min) and the z value was 5.8 ¡ãc.
%K enzyme
%K optimum temperature
%K optimum ph
%K enthalpy
%K entropy
%K gibbs free energy.
%U http://www.scielo.br/scielo.php?script=sci_abstract&pid=S1981-67232012000100005&lng=en&nrm=iso&tlng=en