【摘要】 作者用变形链球菌、血链球菌、唾液链球菌、干酪乳杆菌及粘性放线菌等五种致龋菌体外混合培养,模拟牙菌斑生态系,研究细菌在混合状态下,细胞外多糖合成。结果表明,五种实验菌都能利用蔗糖合成细胞外水溶性和水不溶性多糖。与血链球菌、变形链球菌混合培养,能显著增加细胞外多糖产量;与干酪乳杆菌混合培养,则明显减少多糖产量。更多还原

【Abstract】 Five cariogenic bacteria:S. mutans, S.sanguis, S. salivarius, A. viscosus and L.casei were incubated in mixed cultures con-taining 3% sucrose. Extracellular water-soluble polysaccharides and water-insolublepolysaccharides were collected separatelyfrom 48h cultures by alcohol precipitationmethod. The amounts of the two kinds ofpolysaccharides were measured by anthronemethod. The results showed that all teststrains could produce extracellular polysac-charides from sucrose, mainly water-sloublepolysaccharides. When the other strains ofbacteria were incubated with S. mutans orS. sanguis, the amounts of polysaccharidesincreased significantly. L. casei producedthe smallest amount of polysaccharides.Whenthe other straine were mixed with it, theamounts of polysaccharides produced droppedsignificantly.更多还原