Abstract
The extracellular dextran elaborated by Leuconostoc mesenteroides NRRL B-1299, which was shown to be heterogeneous, was separated into five fractions by assorted fractionation methods. Each fraction turned out to be homogeneous by ultracentrifugation and/or electrophoretic analysis. Gel filtration analysis suggested that these fractions were divided into two groups on the basis of their average molecular weights, one of which had comparatively low molecular weight of 150, 000_??_200, 000 (BPS and CPS) and the other had high molecular weight of about 2, 000, 000 (BPP, CPP and CS). From the results of periodate oxidation, each fraction was shown to contain 41_??_46% of 1, 6-glucosidic linkage (including non-reducing terminal group) as well as 1, 4- like (1, 4- and/or 1, 2-) and 1, 3-like linkages. Partial acid hydrolysis of each fraction yielded a series of α-1, 6-linked oligosaccharides and acetolysis gave kojibiose and nigerose. Moreover, these fractions gave characteristic precipitation patterns, when incubated with concanavalin A. On the basis of these results, the structural features of the fractions were discussed.
