Cell wall receptors of the lectins produced by Kluyveromyces bulgaricus

The flocculent yeast Kluyveromyces bulgaricus excreted Gal and GlcNAc-specific lectins in the culture medium. The two lectins were also extracted from whole cells by incubation with a 0.2 M Gal solution, in sodium acetate buffer pH 4.5, in the presence of calcium. This treatment induced a dispersion of the flocs, but the cells, after wash in sodium acetate buffer, slowly flocculated again, with a low degree. This observation prompted the authors to investigate the presence of non-Gal-extractable compounds on the wall, implicated in cell-cell adhesion. The presence of hydrophobic substances on the cell surface, involved in flocculation, was evidenced by ethanol treatment of the cells. The Gal-specific lectin was able to flocculate previously dispersed K. bulgaricus cells, but the authors failed to detect Gal in the wall polysaccharides of this strain.