变形链球菌葡糖基转移酶缺陷突变株合成葡聚糖的扫描电镜观察

Ultrastructure of glucan produced by streptococcus mutans MT8148 and its glucosyltransferase deficient mutants

采用扫描电子显微镜观察在蔗糖存在下变链ＭＴ８１４８及其葡糖基转移酶缺陷突变株Ｂ２９、Ｂ５８和Ｂ３２合成葡聚糖的超微结构。结果在蔗糖存在下，变链ＭＴ８１４８及其ＧＴＦＳＩ缺陷株菌体表面和菌体间有大量丝状、不定形物质，而ＧＴＦＩ缺陷株Ｂ２９、ＧＴＦＩ和ＧＴＦＳＩ缺陷株Ｂ３２菌体表面光滑，菌体间无不定形物质，表明在变链ＭＴ８１４８、Ｂ５８菌体表面和菌体间的不定形物质为ＧＴＦ１酶产物－非水溶性葡聚糖。

The ultrastruture of extracellular glucan produced in colonies by streptococcus mutans MT8148 and its glucosyltransferase deficient mutants were compared with electron microscopy.A large amount of glucan was produced from sucrose by colonies of S.mutans MT8148 and its CFGTase deficient mutant B58.The glucan showed filamentous and amorphous structure.However,no such structure was observed in the colonies of B29.of a CAGTasedeficient mutant,and of B32,of a CAGTase and of CFGTase both deficient mutant.This result indicates that the filamentous and amorphous structure is the CAGTase product,water-insoluble glucan.