Adhesion of bifidobacteria to Caco-2 in vitro and analysis of surface traits of bifidobacteria

Abstract:

Abstract: [Objective] The purposes of this paper were to evaluate the adhesion ability of bifidobacteria in vitro and analysis its surface properties. [Methods] We selected Caco-2 cell as the adhesion model to determine the adhesion ability of 7 bifidobacterial strains in vitro. The autoaggregation ability and surface hydrophobicity were also assayed; moreover, the substance on the surface of bifidobacteria related to adhesion was characterized by treatments of different enzymes and chemicals, and surface proteins of bifidobacteria were analyzed by electrophoresis. [Results] The strain with high surface hydrophobicity and strong autoaggregation ability also showed higher adhesion ability than the strain with low surface hydrophobicity and weak autoaggergation. The correlation among the three properties was obvious. On the other hand, the adhesion of bifidobacteria was sensitive to proteinase and metaperiodate, and the adhesion ability of bifidobacteria decreased significantly after the surface protein extracted with LiCl. The result of SDS-PAGE showed that many proteins with different molecule weights were extracted from bifidobacteria by LiCl. [Conclusion] It could be concluded that bifidobacteria adhering to Caco-2 cell was strain-specific; surface hydrophobicity and autoaggregation ability of bifidobacteria exhibited positive correlation to the adhesion ability. On the other hand, glycoprotein might exist on the surface of bifidobacterial cells which could mediate the adhesion ability of bifodobacteria.