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

Evidence is provided for the synthesis of hetero-oligosaccharides by Termam yl, the thermotolerant ol-amylase from Bacillus lichenifomis. In the presen ce of soluble starch and added non-starch sugars (isomaltose, cellobiose, m annose, melibiose, stachyose, xylose and 1-o-methyl-beta-D-glucopyranoside) , oligosaccharides were produced by the reversed catalytic reaction. New pe aks of homo- and hetero-oligosaccharides (DP1-10) were detected by high per formance anion exchange chromatography (HPAEC) in equilibrium reaction mixt ures. Attempts to increase the extent of synthesis of oligosaccharides usin g organic solvents (ethanol, methanol, N-propanol, propanediol, N-butanol, dioxane and dimethyl sulfoxide (DMSO)) to lower the water activity of the r eaction mixture were unsuccessful. Raising the temperature of the reaction mixture from 37 degrees C to 55 degrees C was ineffective. (C) 2000 Elsevie r Science B.V. All rights reserved.