Improved synthesis of disaccharides with Escherichia coli β-galactosidase using bio-solvents derived from glycerol

A noticeably increase in activity, keeping total regioselectivity was found in the synthetic behaviour of Escherichia coli beta-galactosidase in glycerol-based solvents using a 1:7 molar ratio of donor (pNP-beta-Gal): acceptor (GlcNAc). Yields of up to 97% of beta(1 -> 6) with different solvents were found. These reactions take place without noticeable hydrolytic activity and with total regioselectivity, representing a considerable improvement over the use of aqueous buffer or conventional organic solvents. There is a clear dependence of the catalytic results on the solvent structure, which is analysed in terms of polarity and hydrophobicity. (C) 2011 Published by Elsevier Ltd.