Saccharomyces cerevisiae polysaccharide

Yeast Insoluble Polysaccharide. The structure of an insoluble polysaccharide from the yeast Saccharomyces cerevisiae was investigated by Zechmeister and Toth,90a and also by Hassid, Joslyn and McCready.904 The isolation904 of 2,4,6-trimethyl-D-glucose as the sole product of the hydrolysis of the methylated polysaccharide indicated a chain of gluco-pyranose units joined by 1,3-glucosidic linkages. 

The structure of mannose-rich polysaccharide core in GL4 is close to that of yeast mannan (from Saccharomyces cerevisiae), which was inactive for IL-6 induction in a human peripheral whole-blood cells test system. This fact suggests that not the mannose moieties but other components, such as the lipophilic moiety and/or phosphates, are important for the activity. The lipophilic products in HF-hydrolysate of GL4 were then analyzed. In addition to peaks corresponding to the known fatty acids (C16 0, C18 1), two other unknown ion peaks at m/z 330 and 356 were found by FAB-MS (data not shown). 

The cell wall of Saccharomyces cerevisiae has a structure of crossed molecules of /3-D-linked D-glucan, which gives the wall its strength and the cell its shape. This glucan is embedded in other polysaccharide(s) or in glycoprotein. Thus, yeast cell-walls consist mainly of polysaccharide, with relatively little protein, lipid, or min-... 

Mannan was discovered in bakers yeast (Saccharomyces cerevisiae) by Salkowski in 1894 at that time, it was termed yeast gum. The first detailed studies of its structure were made by the methyl-ation procedure by Haworth and coworkers. - The results showed that the polysaccharide consists entirely of D-mannose residues and is highly branched, the D-mannose residues being combined by (1 2)-, (1 3)-, and (1 — 6)-linkages. Its molecular weight, as... 

Chitin is almost always found as crystalline microfibrils usually embedded in a matrix constituted of other polysaccharides. For example, in Saccharomyces cerevisiae(19), chitin is found in the form of microfibrils along with fibrilar (1-+3)-6-D-gl ucan. The latter is also found in other species as a matrix polysaccharide embedding the chitin microfibrils as in Schizophyl1 urn commune.(31) This composite material is also associated with (l>TJ-3-D-glucan to constitute the final cell wal1. 

Most of the fungal cell wall is composed of polysaccharides (80-90%) with the remainder consisting mainly of lipid and protein. There seems to be no correlation between cell wall lipid amounts and the genus examined. Most of the cell wall lipid is bound and relatively difficult to extract. In S.cerevisiae, neutral lipids and phosphoglycerides are major components while in Candida albicans sterol esters, sterols, fatty acids, triacylglycerols and phospholipids are all contained. Thus, in contrast to Saccharomyces spp., the Candida spp. contain mainly sterols and sterol esters (40-60% total). 

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