Oligosaccharide synthesis by reversed catalysis using α-amylase from Bacillus licheniformis

Evidence is provided for the synthesis of hetero-oligosaccharides by Termamyl, the thermotolerant α-amylase from Bacillus licheniformis. In the presence of soluble starch and added non-starch sugars (isomaltose, cellobiose, mannose, melibiose, stachyose, xylose and 1-o-methyl-β-d-glucopyranoside), oligosaccharides were produced by the reversed catalytic reaction. New peaks of homo- and hetero-oligosaccharides (DP1-10) were detected by high performance anion exchange chromatography (HPAEC) in equilibrium reaction mixtures. Attempts to increase the extent of synthesis of oligosaccharides using organic solvents (ethanol, methanol, N-propanol, propanediol, N-butanol, dioxane and dimethyl sulfoxide (DMSO)) to lower the water activity of the reaction mixture were unsuccessful. Raising the temperature of the reaction mixture from 37°C to 55°C was ineffective.