SYNTHESIS OF CELL WALL POLYSACCHARIDES IN THE CELL CYCLE OF BAKER'S YEAST

Abstract

Cell wall polysaccharide content of small- and large-sized cells which were obtained by fractional centrifugation of commercial baker's yeast was determined. The small-sized cells contained significantly lower amount of glucan and higher amount of mannan than the large-sized cells. Glucan content of small cells obtained by the fractionation of laboratory-cultured cells was also lower than original cells, and increased by various treatments which make the cell size larger. Determination of cell wall polysaccharides during the course of synchronous proliferation of large cells revealed that mannan is synthesized linearly during cell division cycles, whereas glucan synthesis proceeded intermittently; that is, it was seen mainly in the latter half of the cell division cycle. The difference in cell wall polysaccharide content between the small and large cells might be explained from these results and the position of the small cells in the cell division cycle, which was discussed in the preceding paper.