Takamori K, Mizuno F, Matsuda Y, Takahashi N, Horikawa T
Bull Tokyo Med Dent Univ. 1976 Mar;23(1):23-6.
Dextran degrading activity of the human oral microflora was detected by culturing in TYD broth (Tryptose 1.0%, Yeast extract 0.3%, Dextran T-150 (Pharmacia, MW 150,000) 0.15%). All of the plaue and saliva samples collected from 10 subjects showed a dextran degrading activity, both cultured aerobically and anaerobically, while the anaerobic culture was more active than the aerobic. Furthermore, some individual differences were observed in their activity. Crude enzyme(s) was extracted from the supernatant of a mixed culture of plaque sample by adding ammonium-sulfate to 0.6 and 0.8 saturation (called E-1 and E-2, respectively). E-1 contained 2 dextran-degrading enzymes, one being thought to be an endo-enzyme, with the optimal of H being 5.0 and the other an exo-enzyme with the optimal pH being 7.0-7.5. On the other hand, E-2 contained 1 enzyme of the endo-type. Thirteen strains producing dextranase were isolated from the plaque and were identified as Bacteroides oralis-like organisms. Several other organisms were thought to produce dextranase, although we failed to isolate them in this experiment.
通过在TYD肉汤（胰蛋白胨1.0%、酵母提取物0.3%、葡聚糖T - 150（Pharmacia，分子量150,000）0.15%）中培养来检测人类口腔微生物群的葡聚糖降解活性。从10名受试者采集的所有菌斑和唾液样本在需氧和厌氧培养条件下均表现出葡聚糖降解活性，其中厌氧培养比需氧培养更活跃。此外，还观察到它们在活性方面存在个体差异。通过向菌斑样本混合培养物的上清液中加入硫酸铵至饱和度0.6和0.8（分别称为E - 1和E - 2）来提取粗酶。E - 1含有2种葡聚糖降解酶，一种被认为是内切酶，最适pH为5.0，另一种是外切酶，最适pH为7.0 - 7.5。另一方面，E - 2含有1种内切型酶。从菌斑中分离出13株产生葡聚糖酶的菌株，并鉴定为类口腔拟杆菌。尽管在本实验中未能分离出其他几种被认为能产生葡聚糖酶的微生物，但它们也被认为具有该能力。
