粘液放线菌生物膜结构中细菌和胞外多糖关系的初步研究

目的探讨粘液放线菌形成的单菌种生物膜的结构以及胞外多糖在生物膜中的分布。方法采用微生物厌氧培养技术将粘液放线菌在玻璃片上形成24h单菌种生物膜，用荧光染料Fluorescein、BODIPY和Calcofluor进行荧光染色，激光共聚焦扫描显微镜观察其形成的生物膜结构和其中胞外多糖的分布。结果玻璃表面粘液放线菌粘附形成致密的生物膜，大量微菌落和沟壑间隙是其所形成生物膜的特征。临近粘附表面的生物膜基底部位细菌密度较低，而中部则较致密。生物膜中胞外多糖分布与菌落中的细菌分布一致。结论粘液放线菌依靠其合成的胞外多糖聚集形成了生物膜。

On the Relationship Between Exopolysaccharides and Actinomyces Viscosus in Biofilms

Objective To elucidate the biofilm structure of Actinomyces viscosus and the spatial distribution of exopolysaccharides in it. Methods The Actinomyces viscosus biofilm was made by allowing bacteria to attach to the cover glass surface. The biofilm structure and exopolysaccharides distribution at 24 hours were stained with Fluorescein, BODIPY and Calcofluor respectively and were visualized by confocal laser scanning microscopy (CLSM). Results Actinomyces viscosus could attach to glass surface and form a structural biofilm where bacteria were embedded in the EPS glycocalyx polymers, and characteristic microcolonies and channels were taking shape. Bacteria were sparse in the substratum area but crowd in the center. In the biofilm, the distribution of bacteria was consistent with the distribution of exopolysaccharides. Conclusion The findings demonstrate an important role of exopolysaccharides in the process of Actinomyces viscosus biofilm formation.