title: Characterization of a β-glucosidase with transgalactosylation capacity from the zygomycete Rhizomucor miehei.
abstract: An extracellular β-glucosidase from the zygomycete Rhizomucor miehei NRRL 5282 cultivated in a wheat bran-based solid state fermentation system was characterized. The purified enzyme exhibited an optimum temperature of 68-70 °C and pH of 5.0. It efficiently hydrolyzed oligosaccharides having β-(1→4) glycosidic linkages and exhibited some β- and α-galactosidase activity. The V(max) for p-nitrophenyl-β-d-glucopyranoside and cellobiose was 468.2 and 115.5 U/mg, respectively, while the K(m) was 0.12 mM for both substrates. The enzyme had transglucosylation and transgalactosylation activities resulting in the formation of glycosides from cellobiose, lactose and ethanol. The enzyme increased the amounts of free phenolic antioxidants in sour cherry pomace indicating that its hydrolyzing activity could potentially be applicable to improve the bioavailability of these compounds.
authors.affiliation: Institute of Food Engineering, Faculty of Engineering, University of Szeged, H-6725 Szeged, Mars tér 7, Hungary.
authors.forename: Judit
authors.initials: J
authors.lastname: Krisch
authors.forename: Ottó
authors.initials: O
authors.lastname: Bencsik
authors.forename: Tamás
authors.initials: T
authors.lastname: Papp
authors.forename: Csaba
authors.initials: C
authors.lastname: Vágvölgyi
authors.forename: Miklós
authors.initials: M
authors.lastname: Takó
mesh_terms: D004789:Enzyme Activation; D004795:Enzyme Stability; D005690:Galactose / Q000737:chemistry* / Q000378:metabolism*; D020103:Rhizomucor / Q000145:classification* / Q000201:enzymology*; D013045:Species Specificity; D001617:beta-Glucosidase / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D001617:beta-Glucosidase; D005690:Galactose