Enzymatic Synthesis of Galactooligosaccharides by the Condensation Action of Thermostable α-Galactosidase from Pycnoporus cinnabarinus

Abstract

Three kinds of trisaccharides were synthesized using condensation action of α-galactosidase (EC 3.2.1.22) from pyrcnoporus cinnabarinus on the mixture of galactose and sucrose. The condensation products were isolated and their structures were investigated by acid and enzymatic hydrolysis, and methylation analysis. The three trisaccharides isolated were identified as raffinose, planteose, and 3^G-α-galactosylsucrose. Conditions for synthesis of the trisaccharides by condensation action of the α-galactosidase were studied. The yield of the trisaccharides was approximately 15% based on the amount of galactose used, when α-galactosidase (40 units/ml) was incubated with 10% (w/v) galactose and 60% (w/v) sucrose for 48h at pH 5.0 and 60°C.