Biomaterial Database

Inhibition of acid production in Streptococcus mutans R9 by formic acid. 1996

S J Assinder, and H A Popiel

MRC Dental Group, Dental School, Bristol, UK. s.j.assinder@bristol.uk.ac

Both lactic and acetic acids cause mixed inhibition of acid production in mutans streptococci. This inhibition is partly irreversible due to cell death, an important factor when considering acidogenicity and aciduricity of these organisms, and their role in the caries process. Other monocarboxylic end-products may be present and may also be important inhibitors of acid production in dental plaque. This study considered the effects of varying concentrations of the end-product formic acid on acid production rates in Streptococcus mutans R9, measured using the pH-stat. Undissociated formic acid caused mixed inhibition with constants of Kiu (uncompetitive) of 6.07 +/- 1.27 mmol-1 and Kic (competitive) of 0.2 +/- 0.11 mmol l-1. Inhibition was found to be fully reversible, with no loss of cell viability. It is concluded that at those concentrations found in vivo, formate is not a significant inhibitor of acid production by S. mutans in dental plaque at any time, and is not important in determining the acidogenicity or aciduricity of this organism.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D003731	Dental Caries	Localized destruction of the tooth surface initiated by decalcification of the enamel followed by enzymatic lysis of organic structures and leading to cavity formation. If left unchecked, the cavity may penetrate the enamel and dentin and reach the pulp.	Caries, Dental,Carious Lesions,Dental Cavities,Dental Cavity,Dental Decay,Dental White Spots,Carious Dentin,Decay, Dental,Dental White Spot,White Spot, Dental,White Spots, Dental,Carious Dentins,Carious Lesion,Cavities, Dental,Cavity, Dental,Dentin, Carious,Dentins, Carious,Lesion, Carious,Lesions, Carious,Spot, Dental White,Spots, Dental White
D003773	Dental Plaque	A film that attaches to teeth, often causing DENTAL CARIES and GINGIVITIS. It is composed of MUCINS, secreted from salivary glands, and microorganisms.	Plaque, Dental
D005561	Formates	Derivatives of formic acids. Included under this heading are a broad variety of acid forms, salts, esters, and amides that are formed with a single carbon carboxy group.	Formic Acids,Acids, Formic
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D006863	Hydrogen-Ion Concentration	The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH	pH,Concentration, Hydrogen-Ion,Concentrations, Hydrogen-Ion,Hydrogen Ion Concentration,Hydrogen-Ion Concentrations
D013295	Streptococcus mutans	A polysaccharide-producing species of STREPTOCOCCUS isolated from human dental plaque.
D019342	Acetic Acid	Product of the oxidation of ethanol and of the destructive distillation of wood. It is used locally, occasionally internally, as a counterirritant and also as a reagent. (Stedman, 26th ed)	Glacial Acetic Acid,Vinegar,Acetic Acid Glacial,Acetic Acid, Glacial,Glacial, Acetic Acid
D019344	Lactic Acid	A normal intermediate in the fermentation (oxidation, metabolism) of sugar. The concentrated form is used internally to prevent gastrointestinal fermentation. (From Stedman, 26th ed)	Lactate,2-Hydroxypropanoic Acid,2-Hydroxypropionic Acid,Ammonium Lactate,D-Lactic Acid,L-Lactic Acid,Propanoic Acid, 2-Hydroxy-, (2R)-,Propanoic Acid, 2-Hydroxy-, (2S)-,Sarcolactic Acid,2 Hydroxypropanoic Acid,2 Hydroxypropionic Acid,D Lactic Acid,L Lactic Acid,Lactate, Ammonium