本实验对变链菌、粘放菌单独培养和变链菌加粘放菌韦荣氏菌混合培养这三组细菌在含糖培养基中产酸和pH值进行了分析。结果表明:变链菌和粘放菌产生大量乳酸是导致pH下降的主要因素,也是细菌致龋的主要有机酸;而韦荣氏菌与这些细菌之间存在食物链,可将乳酸分解为乙酸和丙酸等弱酸,从而使乳酸量显著减少,pH值有所回升。 In this experiment, the Streptococcus, Streptococcus mutans cultured alone and Streptococcus mutans plus Microfungi Veillonella mixed culture of these three groups of bacteria in sugar-containing medium acid and pH were analyzed. The results showed that a large amount of lactic acid produced by Streptococcus mutans and myxobacteria was the main factor leading to the drop of pH and also the main organic acid causing bacterial caries. However, there was a food chain between Veillonella bacteria and these bacteria, which could decompose lactic acid into acetic acid and Propionic acid and other weak acids, so that a significant reduction in the amount of lactic acid, pH value has picked up.