Glucansucrase acceptor reactions with d-mannose.

The main acceptor product of glucansucrases with d-mannose has not previously been identified. We used glucansucrases that form water-insoluble α-d-glucans to produce increased yields of acceptor products from d-mannose, and identified the major product as 6-O-α-d-glucopyranosyl-d-mannose. Glucansucrases that synthesize insoluble α-d-glucans produced higher yields of the disaccharide compared to typical dextransucrases.