title: Hydrolysis of soybean isoflavones by Debaryomyces hansenii UFV-1 immobilised cells and free β-glucosidase.
abstract: An intracellular β-glucosidase from Debaryomyceshansenii UFV-1 was produced in an YP medium with cellobiose as the carbon source. This enzyme was purified, characterised and presented a Mr of 65.15kDa. Yeast cells containing the intracellular β-glucosidase were immobilised in calcium alginate. The free β-glucosidase and immobilised cells containing the enzyme presented optima values of pH and temperature of 6.0 and 45°C and 5.5 and 50°C, respectively. The free enzyme maintained 62% and 47% of its original activity after 90days at 4°C and after 15days at room temperature, respectively. The immobilisation process resulted in higher enzyme thermostability at 45 and 50°C. Soy molasses treatment with the free enzyme and the immobilised cells containing β-glucosidase, for 2h at 40°C, promoted efficient hydrolysis of isoflavone glicosides to their aglycon forms. The results suggest that this enzyme could be used in the food industry, in the free or immobilised forms, for a safe and efficient process to hydrolyse isoflavone glycosides in soy molasses.
authors.affiliation: Dep. Bioquímica e Biologia Molecular, BIOAGRO, Universidade Federal de Viçosa, Viçosa, MG 36.570-000, Brazil.
authors.forename: Gabriela P
authors.initials: GP
authors.lastname: Maitan-Alfenas
authors.forename: Lorena G
authors.initials: LG
authors.lastname: de A Lage
authors.forename: Maíra N
authors.initials: MN
authors.lastname: de Almeida
authors.forename: Evan M
authors.initials: EM
authors.lastname: Visser
authors.forename: Sebastião T
authors.initials: ST
authors.lastname: de Rezende
authors.forename: Valéria M
authors.initials: VM
authors.lastname: Guimarães
mesh_terms: D018914:Cells, Immobilized / Q000737:chemistry / Q000201:enzymology / Q000378:metabolism; D055165:Debaryomyces / Q000737:chemistry / Q000201:enzymology* / Q000378:metabolism; D004795:Enzyme Stability; D005656:Fungal Proteins / Q000737:chemistry / Q000378:metabolism*; D006868:Hydrolysis; D007529:Isoflavones / Q000737:chemistry / Q000378:metabolism*; D007700:Kinetics; D013025:Glycine max / Q000737:chemistry / Q000378:metabolism*; D001617:beta-Glucosidase / Q000737:chemistry / Q000378:metabolism*
chemical_list: D005656:Fungal Proteins; D007529:Isoflavones; D001617:beta-Glucosidase
keywords: Debaryomyces hansenii UFV-1; Immobilisation; Isoflavones; Soy molasses; β-Glucosidase