Polysaccharide composition of the cell wall of baker's yeast with special reference to cell walls obtained from large- and small-sized cells

Abstract

In order to obtain further information on the mode of cell wall formation during the growth process, the compositions of cell wall polysaccharides were compared in detail using cell wall samples prepared from large and small cells obtained by fractionation of baker's yeast cells. Gas liquid chromatography of the methanolyzed specimen gave stable, reproducible results, when the sample contained both glucose and mannose. Much mannan was liberated from the cell wall during its preparation and this must be taken into consideration. Total glucose and mannose accounted for about 40% each of dry weight of cell walls obtained from large and small cells. Glucans were tentatively divided into alkali-soluble and alkali, acid-insoluble ones. Alkaline extraction caused considerable degradation of polysaccharides. Nevertheless, a distinct difference existed between the glucan contents of the two cell walls. The cell wall sample of large cells contained a higher amount of insoluble glucan, whereas that of small cells contained a higher amount of alkali-soluble glucan. The mode of formation of cell wall polysaccharides during growth was discussed on the basis of a small-to-large cell process.