不同生存状态下变形链球菌合成胞外多糖的研究

A comparative study of exopolysaccharides producedy planktonic and attached Streptococcus mutans

目的 :比较变形链球菌合成水溶性、水不溶性胞外多糖的能力在生物膜黏附状态与浮游状态下是否存在量的差异及其可能原因。方法 :在多种蔗糖培养浓度和不同培养时间 ,对变形链球菌分别进行静置培养和摇动培养 ,以模拟生物膜黏附状态和浮游状态下生长的变形链球菌 ,蒽酮法测定细菌合成的水溶性胞外多糖和水不溶性胞外多糖的含量。结果 :相同培养时间每种蔗糖浓度条件下 ,生物膜黏附状态下变形链球菌合成的水溶性、水不溶性胞外多糖均要多于浮游状态下的细菌 (P <0 .0 5 ) ,生物膜黏附状态与浮游状态下变形链球菌的数量和合成胞外多糖的量均随着时间的增加而增加 ,不同培养时间同一蔗糖浓度条件下 ,生物膜状态下变形链球菌合成的水溶性、水不溶性胞外多糖也多于浮游状态下的细菌 (P <0 .0 5 )。结论 :生物膜黏附条件下 ,变形链球菌合成水溶性、水不溶性胞外多糖的能力均明显增强 ,这可能是生物膜中的细菌有更强致龋性的原因之一。

Objective:Compare the effect of different cultivation conditions ( planktonic vs. attached) on the amount of exopolysaccharides produced by the Str eptococcus mutans. Method:Anthrone Method was applied to me asure the amoun t of soluble and insoluble exopolysaccharides produced by Streptococcus mutans c ultivated in different concentrations of sucrose and time at planktonic conditio n and attached condition.Result:Adhesive Streptococcus mutans p roduced more ex opolysaccharides than that of planktonic ones in varied sugar concentrations and time(P<0.05).Conclusion:Adhesive Streptococcus mutans can produces more exo polysaccharides, which plays an important role in the procession of biofilm form ation and caries occurrence. [