The edible mushroom, Pycnoporus sanguineus, is used to formulate nutraceuticals and functional foods in Asia. The purpose of this research was to investigate the effects of sucrose, glucose, and potato dextrose broth (PDB) as carbon sources on mycelial growth and changes of polysaccharides in sugar composition and molecular weight distribution. The maximum mycelial growth of 10.1 g L (1) was obtained at 40 g L- (1) PDB. Polysaccharides were characterized by size-exclusion chromatography (SEC) and high-performance anion-exchange chromatography (HPAEC). Sucrose or glucose as the substrate enhanced the biosynthesis of very-low-molecular-weight (<1 kDa) polysaccharides. Fucose, galactose, glucose, mannose, and fructose were the dominant sugars in the polysaccharides. Feeding with glucose resulted in a direct dosage effect in the glucose component of the polysaccharides. Also, a positive correlation was observed for the contents of glucose and fructose with increased feeding of sucrose, and that of a negative correlation existed for the contents of galactose. These findings establish a basis for further investigations of the extent to which formation of polysaccharides differed in their structures depending on the kind of carbon source used. (c) 2012 Elsevier Ltd. All rights reserved.