Extracellular heteropolysaccharides from Cryptococcus and Tremella. A possible taxonomic relationship.

Abstract

Unisexual forms of certain Tremella species produce extracellular acidic heteropolysaccharides when grown on media containing glucose. The isolated polysaccharides contain the same components found in polymers produced by strains of Cryptococcus laurentii, i.e., D-glucuronic acid, D-xylose, D-mannose, and O-acetyl. Optical rotations and molar ratios of components were determined. The polysaccharides are characteristic of the various species of Tremella which produce them. Some of these species produce polymers that contain much higher proportions of xylose than are found in the polymers produced by C. laurentii. Those tremellae that produce polymers resembling C. laurentii polysaccharides also give similar carbon assimilation patterns, but tremellae that produce polymers of higher xylose content also assimilate fewer carbon compounds. These findings, together with similarities in starch synthesis and morphology, suggest a relationship between some species of Tremella and Cryptococcus.