@article{Mai Phuong_Ha_Tra_Nhung_2013, title={Effect of some weak acids and phytochemicals on malolactic fermentation by Streptococcus mutans}, volume={35}, url={https://vjs.ac.vn/index.php/vjbio/article/view/3394}, DOI={10.15625/0866-7160/v35n3.3394}, abstractNote={<p><em>Streptococcus mutans</em> and other certain oral lactic-acid bacteria have demonstrated to possess the ability to carry out malolactic fermentation involving decarboxylation of L-malate to yield L-lactic acid and concomitant reduction in acidity. The activity is inducible by L-malate in <em>S. mutans</em> growing in suspensions or biofilms. Alkalinization is associated with malolactic fermentation resulted in pH rise. Malolactic fermentation (MLF) has been identified as a major system for alkali production by oral streptococci, including <em>S. mutans</em>. Our major objectives in the work described here were to examine the effects of weak acids and some phytochemicals on MLF by <em>S. mutans</em> in both suspension and biofilm states. The obtained data indicated that all week acids tested including triclosan, indomethacin, carpric acid, fluoride and lauric acid inhibited MLF by <em>S. mutans</em> at IC<sub>50</sub> of 0.22, 0.25, 0.08, 4.8 và 2.2 mM, respectively. The biofilm cells were also sensitive to the tested agents but at concentration of 10 to 50 folds<sub> </sub>higher compared to the suspension cells. The inhibition was in a pH dependent manner with increased inhibition was found at lower pH values. For phytochemicals, including a-mangostin and asiatic acid, only a-mangostin showed to be potent for MLF of cells in both suspension and biofilms with IC<sub>50</sub> of ca. 45 and > 120 mM, respectively. Asiatic acid had no effect on MLF even at a high concentration of > 50 mM. The net conclusion is that MLF of <em>S. mutans</em> is sensitive to a-mangostin and weak acids, including fluoride and triclosan, which are commonly added to oral care products.</p>}, number={3}, journal={Academia Journal of Biology}, author={Mai Phuong, Nguyen Thi and Ha, Hoang Phuong and Tra, Pham Thi and Nhung, Tran Thi}, year={2013}, month={Oct.}, pages={376–382} }