CELL-WALL COMPOSITION OF ZYGOSACCHAROMYCES-ROUXII AFTER A SHIFT TO A HIGH-CONCENTRATION OF NACL

We examined the change of the composition of the cell wall polysaccharides prepared from cells of the salt-tolerant yeast Zygosaccharomyces rouxii grown in two media containing 20% NaCl and 0% NaCl. Comparative analysis of their walls showed that the wall obtained from salt-free medium had greater quantities of alkali-insoluble fraction and smaller quantities of mannan than the walls obtained from 20% NaCl medium. The alkali-insoluble fractions from the cell walls obtained from salt-free medium contained a large amount of glucosamine and a smaller amount of linear beta-1,3-glucosidic linkage than the fractions from the cell walls obtained from 20% NaCl medium. Structural analyses showed that the mannans from each cell wall contained an alpha-1,6-mannosidic linked backbone to which single mannose and mannobiose units were connected as side chains by alpha-1,2-mannosidic linkages. However, when cells were grown in the presence of 20% NaCl, the side chains of the mannans consisting of a mannobiose unit were largely reduced. These results indicated that the structure of alkali-insoluble glucan and mannan were greatly affected by the presence of NaCl in the final medium.