Imobilização enzimática de neutrase® em suportes híbridos de quitosana – alginato de sódio – Saccharomyces cerevisiae.

Abstract

The enzyme immobilization constitutes an alternative to increase the use of enzymes in the industry. The immobilization consists in the confinement, by chemical and/or physical methods, of a enzyme in a portion of space, making it physically or chemically associated to a support or matrix. A major advantage of this process is the retainment of the enzyme's catalytic ability for a longer period of time. The Neutrase® enzyme is a protease, which is used in the cheese's protein hydrolysis to obtain certain derivatives whose functional properties are attractive in the production of supplements for special diets, especially for individuals with congenital deficiencies in protein metabolism. The main goal of this work is to characterize the immobilization of Neutrase® in terms of parameters of immobilization, thermal stability and enzyme kinetics, in the supports of chitosan 2,5% - sodium alginate 2,5% and chitosan 2,5% - alginate sodium 2,5% - Saccharomyces cerevisiae 5%, both activated with epichlorohydrin. Immobilization was performed at 25 ° C, pH 10 and stirring for three hours. The catalysis assays were performed at the temperature of 50 ° C. The thermal stability was evaluated at 60 ° C. The measurement of the activity was based on the formation of the amino acid tyrosine, which had its quantification assessed by spectrophotometric method at 700nm. The immobilization on chitosan 2,5% - sodium alginate 2,5%, had a immobilization rate (RI%) of 84%, the recovered activity (Arec%) of 23%, the stabilization factor (EF) of 29,4 and the maximum speed (Vmax) of 3,8 U/mL. The support chitosan 2,5% - sodium alginate 2,5% - Saccharomyces cerevisiae 5%, had RI% 44%, Arec% 86%, EF 394,6 and Vmax of 23,8 U/mL, resulting in the substrate with the greater benefits for the enzyme application after immobilization.