Possible mechanism of co-flocculation between non-flocculent yeasts

Co-flocculation between cells of S. cerevisiae NCYC 234 and NCYC 1109, both of which were non-flocculent when cultivated in MM medium for 20 h, was investigated by chemical modification. Ca2+ promoted co-flocculation. Protein-denaturants and several carbohydrates caused reversible inhibition of the co-flocculation in the presence of Cn(2+). The effect of treatment with proteolytic enzymes and chemical modification of cell surface protein and carbohydrate components suggest strongly that co-flocculation between cells of NCYC 234 and cells of NCYC 1109 results from interaction between surface protein component of cells of NCYC 1109 and surface carbohydrate component of cells of NCYC 234.