Characterization of novel galactosylated chitin-oligosaccharides and chitosan-oligosaccharides

This study determined whether chitin-oligosaccharides and chitosan-oligosaccharides (COS) are suitable acceptor carbohydrates for the LacLM-type beta-galactosidase of Lactobacillus plantarum. Enzymatic reactions were carried out with lactose as galactosyl-donor and chitinbiose (N, N'-diacetyl chitobiose), chitintriose (N, N'N-triacetyl chitotriose) or a highly deacetylated COS preparation with a degree of polymerization ranging from 2 to 4 as galactosyl acceptors. Transgalactosylated oligosaccharides were identified by liquid chromatography-mass spectrometry (LC-MS/MS). LC-MS/MS analysis demonstrated formation of mono-and digalactosylated chitinbiose, mono-galactosylated chitintriose, and mono-, di-, and trigalactosylated COS. beta-(1 -> 4)-Linkages were formed during the galactosylation of chitinbiose and chitintriose. In conclusion, the conversion of lactose with beta-Gal from Lb. plantarum and chitin-oligosaccharides or COS as glycosyl acceptors allows the production of novel oligosaccharides. (C) 2014 Elsevier Ltd. All rights reserved.