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Table 1 The effect of glucose and low pH on the stability of a microbial community. A mixed culture of 9 oral bacteria (representative of those found in health and disease) were grown in a mucin-based medium at a constant pH 7.0. In independent experiments, the culture was pulsed daily on 10 consecutive days with 28 mM glucose. In one culture the pH was maintained throughout the pulsing at pH 7.0, while in other experiments the pH was allowed to fall by bacterial metabolism for 6 hours to pre-set levels of pH 5.5, 5.0 or 4.5. In a final study, the pH was allowed to fall without any pH control imposed [28,29]. Viable counts were determined on selective and non-selective media; proportions are shown after the final glucose pulse for two species implicated in caries and for two species associated with sound enamel

From: Dental plaque as a biofilm and a microbial community – implications for health and disease

Bacterium Percentage of total viable count (%)
  Pre-pulse pH 7.0 5.5 5.0 4.5 no pH control
Streptococcus mutans 0.3 1.0 4.2 7.9 9.6 18.9
Lactobacillus rhamnosus 0.1 0.2 2.4 6.2 13.9 36.1
Streptococcus gordonii 28.3 25.0 2.6 6.9 2.7 0.2
Fusobacterium nucleatum 15.2 9.5 7.4 2.3 2.7 <0.001