THE FLOCCULATION OF WINE YEASTS - BIOCHEMICAL AND MORPHOLOGICAL-CHARACTERISTICS IN KLOECKERA-APICULATA

The floc-forming ability of flocculent strains of Kloeckera apiculata, isolated from musts, was tested for susceptibility to proteinase and sugar treatments. Three different flocculation phenotypes were discrim inated by protease digestion, whereas the inhibition of flocculation b y sugars distinguished two definite patterns: one mechanism of floccul ation involved a galactose-specific protein and the other a broad-spec ificity lectin. SEM and TEM observation of the cell surface of two dif ferent Kloeckera strains revealed fine fibrils and a diffuse structure at the point of contact in one strain, and thick masses of mucus on t he cell wall of the other strain.