Extracellular polysaccharides of some basidiomycetes

Culture filtrates of four basidiomycete fungi, Stereum strigoso-zonatum, Fomes australis, Trametes lilacinogilva and Polyporus tumulosus were fractionated and examined for polysaccharide content. Acid hydrolysis showed the presence of galactose, mannose, xylose, fucose and glucose. Their relative amounts were estimated by gas chromatography of the corresponding alditol acetates. Galactose and mannose were the major constituent sugars, amounting to more than 50% of the total. One of the polysaccharides, a fucogalactomannan elaborated by P. tumulosus, was isolated in a purified form. It was shown to have [alpha]D +42 degrees and contained galactose, mannose, fucose and xylose in the relative proportions 2 : 1 : 1 : 0-2.