Studies on the polysaccharides of capsulated yeasts

Abstract

The properties of a carbohydrate material which stains blue with iodine, isolated from cultures of Torulopsis rotundata, T. neoformans and other capsulated yeasts, are described. The material is a mixture of starch and pentosan derived from the capsule of the yeast. The capsular material consists of a large carbohydrate fraction (c. 70%) and a non-carbohydrate one. The carbohydrate constituent is composed of a zymohexose (15%) and a pentose (85%). The reported expts. have led to a tentative identification of the zymohexose as glucose and of the pentose as d-xylose. The demonstration in cells of T. rotundata of a phosphorylase which synthesizes starch is recorded.