双歧杆菌体外对Caco-2的黏附及其表面性质分析

【目的】体外测定双歧杆菌的黏附能力并对其表面性质进行分析。【方法】利用Caco-2细胞作为黏附模型体外测定七株菌的黏附能力,同时分析其自动聚集能力和表面疏水性,通过采用不同酶及化学物质处理双歧杆菌菌体细胞表面初步确定双歧杆菌细胞表面黏附相关化合物的类型,并对双歧杆菌表面蛋白进行电泳分析。【结果】自动聚集能力和表面疏水性均高的双歧杆菌菌株,其黏附能力高于自动聚集能力和表面疏水性均低的菌株,表现出明显的正相关。此外,受试菌株的黏附能力对蛋白酶和高碘酸钠敏感,利用LiCl对菌体表面蛋白进行提取后,其黏附能力明显下降,SDS-PAGE结果表明LiCl提取物中含有分子量大小不等的多个蛋白。【结论】双歧杆菌体外对Caco-2细胞的黏附具有菌株特异性,其黏附能力与表面疏水性质和自动聚集能力相关,此外,推测双歧杆菌表面可能含有能调节其黏附的糖蛋白类物质。

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

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.