Purification and characterization of Aspergillus terreus α-Galactosidases and their use for hydrolysis of Soymilk Oligosaccharides

• Autor(a) principal: Ferreira, Joana Gasperazzo
• Data de Publicação: 2011
• Outros Autores: Reis, Angélica Pataro, Guimarães, Valéria Monteze, Falkoski, Daniel Luciano, Silva Fialho, Lílian da, Rezende, Sebastião Tavares de
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: https://doi.org/10.1007/s12010-011-9198-y; http://www.locus.ufv.br/handle/123456789/18612
• topic: α-Galactosidase; Aspergillus terreus; Raffinose; Stachyose; Soybean; Anti-nutritional factors

α-Galactosidases has the potential to hydrolyze α-1-6 linkages in raffinose family oligosaccharides (RFO). Aspergillus terreus cells cultivated on wheat bran produced three extracellular forms of α-galactosidases (E1, E2, and E3). E1 and E2 α-galactosidases presented maximal activities at pH 5, while E3 α-galactosidase was more active at pH 5.5. The E1 and E2 enzymes showed stability for 6 h at pH 4–7. Maximal activities were determined at 60, 55, and 50°C, for E1, E2, and E3 α-galactosidase, respectively. E2 α-galactosidase retained 90% of its initial activity after 70 h at 50°C. The enzymes hydrolyzed ρNPGal, melibiose, raffinose and stachyose, and E1 and E2 enzymes were able to hydrolyze guar gum and locust bean gum substrates. E1 and E3 α-galactosidases were completely inhibited by Hg2+, Ag+, and Cu2+. The treatment of RFO present in soy milk with the enzymes showed that E1 α-galactosidase reduced the stachyose content to zero after 12 h of reaction, while E2 promoted total hydrolysis of raffinose. The complete removal of the oligosaccharides in soy milk could be reached by synergistic action of both enzymes