Evidence for a lectin in Kluyveromyces sp that is involved in co-flocculation with Schizosaccharomyces pombe

Co-flocculation is the aggregation of yeasts belonging to different genera or species. Kluyveromyces bulgaricus and Kluyveromyces lactis jc are self-f locculent, but they can also co-flocculate with the non-flocculent yeast Sc hizosaccharomyces pombe 972 h(-). This co-flocculation is inhibited by D-ga lactose and galactose derivatives and involves the binding of a galactose-s pecific proteinic receptor (or lectin) of Kluyveromyces sp, to the cell wal l galactomannans of S. pombe. The proteinic receptor is strongly anchored i n the cell wall, it was partially purified by affinity chromatography using immobilized S. pombe galactomannans. This galactose-specific proteinic rec eptor does not appear to interfere in K. bulgaricus or K lactis self-floccu lation, which is mediated by another galactose-specific lectin weakly linke d at the cell wall. (C) 2000 Federation of European Microbiological Societi es. Published by Elsevier Science B.V. Ail rights reserved.