Strain- and matrix-dependent adhesion of Lactobacillus plantarum is mediated by proteinaceous bacterial compounds

The ability of 31 Lactobacillus plantarum strains to adhere to biological matrixes was evaluated, and the molecules involved in adherence were studied. Mucin, basement membrane proteins and Caco-2 cells were used in adhesion tests. These in vitro assays, together with a yeast agglutination test, were found to be discriminative for screening Lact. plantarum strains for adhesion. Some strains, such as 299v, CBE, BMCM12, Col4S and T25, were shown to possess interesting adhesion properties in at least two models. The adhesion of these strains was strongly inhibited when the bacterial cells were pretreated with trypsin. Lithium chloride and methyl-alpha-D-mannoside also inhibited adhesion to a lower extent. The adhesion of Lact. plantarum depends on both the model and the strain used. The chemical and enzymatic pretreatments applied to the bacterial cells suggested that lectin-like adhesins and other proteinaceous cell-surface structures are involved in adhesion of these strains. We found a great diversity in the adhesion properties between Lact. plantarum strains. Based upon the adhesive property of these strains interesting candidates were identified, that will undergo further study as potential probiotics.