Yeast Flocculation: Influence of Nutritional Factors on Cell Wall Composition

1 Laboratoire de Biochimie Microbienne, Université de Nancy I, 5 rue A. Lebrun, B.P. 403, F-54001 Nancy Cedex, France 2 Centre de Recherche et de Développement Tepral, 2 rue Gabriel Bour, F-54250 Champigneulle, France ABSTRACT Summary: 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 Ca 2+ 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 (Ca 2+ 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 Ca 2+ and a higher percentage of K + .