Comparative structural studies on acidic heteropolysaccharides isolated from "Shirokikurage," fruit body of Tremella fuciformis Berk, and the growing culture of its yeast-like cells.

Abstract

Acidic heteropolysaccharides, D-glucurono-D-xylo-D-mannans were isolated from the water- and alkaline extracts of the fruit body of Tremella fuciformis Berk. Similar poly-saccharides were isolated from the growing culture of the haploid cells of two strains (T-19 and T-7) of T. fuciformis, when they were cultured in sucrose or glucose-yeast extract medium. The extracellular polysaccharides contain, n-glucuronic acid, D-xylose and n-mannose [molar ratios, 1.3: 1.0: 3.5 (T-7) and 0.8: 1.0: 2.1 (T-19)], and, in addition, small proportions of L-fucose and O-acetyl groups. Methylation and Smith degradation studies indicated that both fruit body and extracellular polysaccharides are built up of α-(1→3)-linked D-mannan back-bone chain to which β-linked D-glucuronic acid and single or short chains of β-(1→2)-linked D-xylose residues are attached at the C-2 position. L-fucose residues in the extracellular poly-saccharides may form the single branches. The structural features of these polysaccharides are discussed in comparison with the similar polysaccharides from other fungi.