Open AccessEnhanced acid resistance of oral streptococci at lethal pH values associated with acid‐tolerant catabolism and with ATP synthase activity
Author(s) -
Sheng Jiangyun,
Marquis Robert E.
Publication year - 2006
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2006.00374.x
Subject(s) - streptococcus mutans , catabolism , lactic acid , atpase , glycolysis , biochemistry , atp synthase , bacteria , chemistry , chemiosmosis , enzyme , microbiology and biotechnology , biology , genetics
Caries‐causing oral bacteria such as Streptococcus mutans are protected by the actions of F‐ATPases against acid damage in dental plaque acidified by glycolytic acid production or ingestion of acids foods and beverages. Catabolites such as glucose and sucrose were found to enhance the protection of S. mutans and also other oral lactic‐acid bacteria against acid killing at lethal pH values as low as 2.5. Protection involved glycolysis with the production of lactate and ATP, which is a substrate for F‐ATPases. ATP could also be produced by starved cells apparently through synthase activity of the F‐ATPase associated with acid decline. Fluoride and the organic weak‐acid indomethacin acted to diminish this protection, as did F‐ATPase inhibitors such as dicyclohexylcarbodi‐imide. Protection against acid killing involving catabolism and synthase activity is likely to be important for plaque cariogenicity.