[Comparison of the metabolism of isolated streptococci and dental plaque]

1. Isolated cultures of Streptococcus mutans form lactic acid as well as small amounts of formic acid and acetic acid during the anaerobic break down of glucose. The composition of the acids in terms of percent is independent of time. 2. Plaque specimens incubated in vitro show a complicated spectrum of substances; propionic and butyric acids are found in addition to lactic, formic, and acetic acids. The composition in terms of percent depends on the incubation period. The percentage of lactic acid drops as the incubation period is extended. 3. Just as the plaque, the product spectrum of isolated streptococci in terms of quantitative composition depends on the buffer capacity.