The effect of arginine on in-vitro acid production by the oral bacterium Streptococcus mutans 10449 in various concentrations of glucose.

Acid production was measured both with constant pH and with the pH being allowed to fall. Under both conditions 10 mM arginine reduced it. There was also evidence that arginine reduced the rate of uptake of glucose by the bacterium. Thus arginine may affect the rate of glucose transport or catabolism by Strep. mutans 10449, and has more than a simple buffering effect on these cultures.