Expression of α-1,3 linkage-containing oligomannosyl residues in a cell-wall mannan of Candida tropicalis grown in yeast extract-Sabouraud liquid medium under acidic conditions

We investigated the cell-wall mannan obtained from Candida tropicalis IFO 1647 strain cells grown in yeast extract-Sabouraud medium at pH 3.0 by two-dimensional homonuclear Hartmann-Hahn spectroscopy. The results indicate that the phosphate group and the side chains containing a β-1,2-linked mannopyranose unit decreased compared to those of mannan from cells grown under conventional conditions (pH 5.9) with concomitant expression of α-1,3 linkage-containing oligomannosyl side chains. The results of acetolysis of these mannans indicated that the presence of α-1,3-linked mannopyranose unit existed in side chains corresponding to pentaose and hexaose, Manpα1-3Manpα1-2Manpα1-2Manpα1-2Man, and Manpα1-2Manpα1-3Manpα1-2Manpα1-2Manpα1-2Man, in the mannan from cells grown at pH 3.0.