Abstract: Yeast β-1,3-glucan was hydrolyzed by the β-1,3-glucanase with Trichoderma strain LE02. The conditions of enzymatic hydrolysis were optimized to improve the solubility of amyloses and obtain the maximum water soluble amylose, while the hydrolysate fractions were analyzed by GPC(gel-permeation chromatography). The maximum yield of water soluble β-1,3-glucan is 52% when 20% substrates with 4 U/ml enzyme are incubated at 55 ℃ in pH4.5 buffer for 2 h. The hydrolysates separated through Sephadex G-100 include three fractions: high-molecular-weightpolysaccharides(Fraction I), oligosaccharides (Fraction II), and low-molecular-weight oligosaccharides (Fraction III). The ratio of Fraction I decreases while Fraction III increases rapidly as the β-1,3-glucan was hydrolyzed. The molecular weight distribution of the hydrolysates hydrolyzed for 2 h is analyzed by GPC and over 66.2% fraction is of the molecular weight larger than 30 kD.

Key words: yeast； &beta, -1,3-glucan； &beta, -1,3-glucanase； hydrolyze；