Study of chymotrypsin multipoint immobilization onto glutaraldehyde-chitosan beads

MAMMARELLA, ENRIQUE; ADRIANO, WELLINGTON; GIORDANO, RAQUEL

BRAZILIAN JOURNAL OF CHEMICAL ENGINEERING

Asociación Brasilera de Ingeniería Química

Lugar: San Pablo, Brasil; Año: 2006

0104-6632

The objective of this work was to study the immobilization of chymotrypsin onto chitosan beads by multipoint covalent binding. This process was optimized using a 25 experimental design of experiments. The selected parameters for this study were i) chitosan concentration (A), ii) gelatin concentration (B), iii) NaOH concentration (C), iv) coagulation temperature (D) and v) glutaraldehyde concentration (E). Three responses were chosen: immobilization yield, coupling yield and stabilization factor of enzyme derivatives at high temperature (55 °C). All the runs at the maximum (+1) and minimum (-1) levels were carried out at random. Four experiments were carried out at the center point coded as 0 (zero), for experimental error estimation. The best conditions to produce the derivative were: 2.0% of chitosan, 1.0% of gelatin, 0.5 M of NaOH for coagulation at 0 °C and 2.5% of glutaraldehyde for activation with responses of 52.0% of immobilization yield, 18.3% of coupling yield and 168-fold more stable than free enzime at 55 °C.