Yeast Flocculation: Influence of Nutritional Factors on Cell Wall Composition

Abstract

The walls of two strains of Saccharomyces uvarum (flocculent and non-flocculent) were isolated from exponential and stationary phase cells after growth in media of different Ca2+ and K+ composition. Flocculation of the walls was identical to that of intact cells. The transition from the non-flocculent to the flocculent state involved alterations of the polysaccharide, protein and mineral (Ca2+ and K+) composition of the walls. The walls of flocculent cells had a higher mannose/glucose molar ratio, a lower percentage of protein, a lower percentage of Ca2+ and a higher percentage of K+.