Enzymatic synthesis of galactooligosaccharides using pressurised fluids as reaction medium

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)This work is focussed on the evaluation of enzymatic synthesis of galactooligosaccharides (GOS) catalysed by beta-galactosidase from permeabilized cell of Kluyveromyces marxianus in different compressed fluids. The experiments were performed in a batch mode reactor, where the effects of enzyme and lactose concentrations and system pressure were evaluated. Results showed significant differences in the maximum GOS concentration among the experimental conditions, where the lactose concentration and enzyme activity were found to be statistically significant. Comparing the GOS productions in the three reaction systems, the supercritical CO2 led to the best results, where the maximum production was 83 gl(-1) while, for propane and n-butane, values of 63.0 and 75.0 gl(-1) were verified, respectively. According to the kinetic results of GOS production in supercritical CO2, a promising route is noted for this system, since the competition between synthesis and hydrolysis was less pronounced compared to the other tested fluids. (C) 2012 Elsevier Ltd. All rights reserved.133414081413Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq