Extracellular Black Yeast Polysaccharide composed of N-Acetyl Glucosamine and N-Acetyl Glucosaminuronic Acid

POLYSACCHARIDES containing N-acylated hexosaminuronic acids as major components have been isolated from bacterial cells 1–4,7 and capsules 5,6 . Most of these polysaccharides are antigens from pathogens 1,2,4,5,7 . Polysaccharides from cells or pathogens, however, are unsuitable for investigations of the basic properties and possible practical value of biopolymers, because they are recovered with difficulty and in low yields. It is significant, therefore, that we have isolated in good yield from cultures of an unidentified black yeast (apparently a non-pathogen) an extracellular polysaccharide composed of residues of N-acetyl glucosamine (GlcNAc) and N-acetyl glucosaminuronic acid (GlcNAcUA) in a molar ratio of approximately 2:1. The composition and extracellular occurrence of this polysaccharide make it unique among those from microorganisms. It is the first practicably obtainable member of a new class of biopolymers to be characterized 1–7 . Additional members of this class are foreseen from our exploratory research.