Agglutination of fifty bacterial strains isolated from gastric-intestinal tract of chickens with yeasts treated with glutaraldehyde and glycine was assayed to study possible adhesion mechanisms to epithelia. It was found tha Lactobacillus fermentum, Lactobacillus fermentum subsp. cellobiosus and Lactobacillus animalis agglutinated yeasts massively and this agglutination was inhibited in each strain by different representative sugaars : agglutination was inhibited in three selected strains with 0.2 M mannose. The three strains agglutinated chicken red blood cells, but did not agglutinate human red blood cells, whereas the agglutinating capacity for other animal erythrocytes was variable.The lectins were partially purified on a Sephadex G-75 column and affinity chromatography. The molecular weight of each of the protein subunits was estimated as about 50-67 kDa using electrophoretic techniques. After treatment with lipase and metaperiodate modifications bacterial superficies and/or liberation of some structures produced an unspecific interaction with increase in the yeast agglutination and hemagglutination. The optimal conditions of work were : pH 6-7, Ca²⁺ 1mM, Mg²⁺ 2mM and 37-42°C.