Original scientific paper
Kinetics and Thermal Properties of Crude and Purified β-Galactosidase with Potential for the Production of Galactooligosaccharides
Anna Rafaela Cavalcante Braga
; Chemistry and Food School, Federal University of Rio Grande (FURG), BR-96201900 Rio Grande, RS, Brazil
Ana Paula Manera
; Food Engineering, University Federal of Pampa (UNIPAMPA), BR-96400000 Bagé, RS, Brazil
Joana da Costa Ores
; Chemistry and Food School, Federal University of Rio Grande (FURG), BR-96201900 Rio Grande, RS, Brazil
Luisa Sala
; Chemistry and Food School, Federal University of Rio Grande (FURG), BR-96201900 Rio Grande, RS, Brazil
Francisco Maugeri
; Faculty of Food Engineering, University of Campinas (UNICAMP), BR-13083862 Campinas, SP, Brazil
Susana Juliano Kalil
; Chemistry and Food School, Federal University of Rio Grande (FURG), BR-96201900 Rio Grande, RS, Brazil
Abstract
β-Galactosidase is an enzyme that catalyzes the hydrolysis of lactose. It has potential importance due to various applications in the food and dairy industries, involving lactose-reduced ingredients. The properties of two β-galactosidase enzymes, crude and purified, from different sources, Kluyveromyces marxianus CCT 7082 and Kluyveromyces marxianus ATCC 16045, were analyzed. The pH and temperature optima, deactivation energy, thermal stability and kinetic and thermodynamic parameters were determined, as well as the ability to hydrolyze lactose and produce galactooligosaccharides. Purification process improved the properties of the enzymes, and the results showed that purified enzymes from both strains had a higher optimum temperature, and lower values of Km, thus showing greater affinity for o-nitrophenyl-β-D-galactopiranoside than the crude enzymes. The production of galactooligosaccharides was also greater when using purified enzymes, increasing the synthesis by more than 30 % by both strains.
Keywords
inactivation kinetics; thermal properties; thermodynamic parameters
Hrčak ID:
99746
URI
Publication date:
29.3.2013.
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