Structure of cell wall and exocellular mannans from the yeast Hansenula holstii: II. Mannans produced in phosphate-limited medium

Abstract

1. 1. Cell wall mannan and exocellular phosphomannan from Hansenula holstii NCYC 560 grown under phosphate-limited conditions were analyzed to determine their structures. 2. 2. Both preparations were homogeneous with respect to molecular weight (1. 10 6), but heterogeneous toward ion-exchange resins. 3. 3. Mannans studied were reduced in their phosphate content with O-acetyl groups replacing most of the phosphates as constituents of these polymers. 4. 4. Both mannans had a branched structure similar to some extent to that described for Saccharomyces cerevisiae cell wall mannan, the main difference being the incorporation of O-acetyl groups within the molecules. 5. 5. A role as ion-exchanger in the outer regions of the cell wall is proposed for these mannans.