Effect of 10-undecynoic acid on acidogenicity and acidurity of <i>Streptococcus mutans</i> UA159.

(A) Glycolytic acid production was determined by monitoring the pH decrease in sucrose solution (1% v/v) over a period of 2 h. (B) Acid tolerance was determined by measuring the survival rate of Streptococcus mutans UA159 at pH = 5.0 on BHI agar plates incubated for 24 h at 37°C. (C) Effects of 10-undecynoic acid on F1F0-ATPase of Streptococcus mutans UA159 was assessed as a relative enzymatic activity compared to untreated control. (D) Effects of 10-undecynoic acid on lactic acid production by Streptococcus mutans UA159 was assessed by determining its levels after 24 h as changes in absorbance measured at 570 nm. Control– 0.1% DMSO, 10-UDYA– 10-undecynoic acid, # p0 and N–CFU counts before (N0, time = 0 h) and after 2 h (N, time = 2 h) treatment in pH = 5.0 culture, respectively.