Extracellular polysaccharides produced by acapsular mutant of Cryptococcus laurentii

Heterogeneous extracellular polysaccharide galactoxylomannan has been isolated from the culture medium of the acapsulated mutant Cryptococcus laurentii 17-3-6 as the main extracellular polysaccharide (90%). Size-exclusion chromatography of precipitated polysaccharides afforded two molecular fractions with molecular mass 75 kDa and 20 kDa. Mannose, galactose, glucose, and xylose ratios were 1.00: 1.16: 0.04: 0.88 and 1.00: 0.25: 0.07: 0.24, respectively.