Polysaccharides characterization by colorimetric (Phenol-Sulfuric acid method)
The content of polysaccharides in the extracts was determined by Phenol-Sulfuric acid method. Two milliliters of standard grade sugar solutions (ranging from 10 and 100 μg/ml concentrations of sugar) and 2 ml of purified polysaccharides from T. fuciformis and A. auricula at 100 μg/ml concentrations were pipetted into a test tube, and 1 ml of 5% phenol solutions were added. Then 5 ml of concentrated sulfuric acids were added rapidly. The tubes were shaken and placed in water bath at 30o C before readings procedure was taken. The colorimetric analysis of all solutions was carried out using a UV–Vis spectrophotometer. The absorbance of the characteristic yellow-orange color was measured at 490 nm for hexose monosaccharide and 480 nm for pentose monosaccharide and uronic acid. Blanks were prepared by substituting distilled water for the sugar solution. The amount of polysaccharides in fungal extracts were determined and expressed as amounts of hexose and pentose sugars by using constructed standard curves of each standard sugar(Dubois et al., 1956).