Imobilização de β-galactosidase de Aspergillus oryzae em resinas de troca iônica

AUTOR(ES)

Carla Zanella Guidini

DATA DE PUBLICAÇÃO

2009

RESUMO

In this work was studied the immobilization process β-galactosidase from Aspergillus oryzae by adsorption and cross-linking with glutaraldehyde, using as carrier ions-exchangers such as Duolite A-568, Duolite S-761, Dowex Marathon A, Dowex Marathon C and Amberlite 252 Na. Through innitial results, Duolite A-568 was choosed for the continuance of the work. The influence of the enzyme concentration and pH in the immobilization process was studied using a Central Composit Design (CCD) for a fixed time of 12 hours and temperature of 25C. The optimal conditions for enzyme immobilization were pH 4,5 and galactosidase concentration 16 g/L. In the sequence, was studied the influence of glutaraldehyde concentration as cross-linking reagent and reaction time in the activity and in stability of the immobilized biocalyst, which were of 3,5 g/L and 1,50 h. The residual activity of the immobilized enzyme without cross-linking with glutaraldehyde after 30 uses was 51% as compared with the initial activity, while the enzyme immobilized with cross-linking was 90%. The immobilized enzyme with cross-linking presented higher pH stabilyt pH when compared to that without the referred treatment. The simultaneous influence of pH and temperature on the immobilized enzyme activity was studied through a PCC with the biocalyst produced in the optimized conditions of immobilization process. With the technique response surface it was possible to obtain the optimized pH of 4,1 and temperature of 34C. The influence of the lactose concentration was studied in the range of 5 to 140 g/L and the Michaelis-Menten model was adjusted to the experimental results, with values of Vm and Km of 0,71 U and 12.07 g/L, respectively. In the study of the influence of the galactose as inhibitor of the lactose hydrolysis, the competitive inhibition model was adjusted to the experimental results and the values of Vm, Km and Ki were 0,77 U, 12,07 g/L and 4,94 g/L respectively.

ASSUNTO(S)

imobilização duolite a-568 immobilization duolite a-568 glutaraldehyde lactose hydrolysis hidrólise da lactose β-galactosidase hidrólise engenharia quimica glutaraldeído

Documentos Relacionados

• Imobilização de α-galactosidase de Aspergillus niger em resina de troca iônica Duolite A-568
• Imobilização da enzima β-galactosidase de Kluyveromyces fragilis em agarose e quitosana utilizando diferentes protocolos de ativação
• Otimização do processo de imobilização de Beta - galactosidase de Aspergillus oryzae em alginato de sódio com gelatina e glutaraldeído
• Um experimento-charada usando data-show e resinas de troca iônica
• Estudo da adsorção de inulinases em colunas com resinas de troca ionica : paramentros experimentais e modelagem