Phosphomannans and Other Components of Flocculent and Non-Flocculent Walls of Saccharomyces cerevisiae

Abstract

SUMMARY: Preparations of flocculent and of non-flocculent cell walls were obtained from flocculent and non-flocculent cells of a strain of Saccharomyces cerevisiae. Flocculent walls contained 46% glucan, 43% mannan, 0.4% P, 1.1% hexosamine, 0.79% non-hexosamine N; non-flocculent walls contained 47% glucan, 44% mannan, 0.3% P, 1.2% hexosamine and 0.98%non-hexosamine N. Mannose-6-phosphate was identified as the principal phosphorus compound present. The mannose residue formed part of the cell-wall mannan and the phosphate was also linked by a second, labile, ester bond to an unidentified site. The degree of phosphorylation of the mannan varied from 1 phosphate to 19 mannose residues in non-flocculent cells to 1 phosphate to 13 residues in flocculent cells.