title: Nitrogenous compounds stimulate glucose-derived acid production by oral Streptococcus and Actinomyces.
abstract: Both Streptococcus and Actinomyces can produce acids from dietary sugars and are frequently found in caries lesions. In the oral cavity, nitrogenous compounds, such as peptides and amino acids, are provided continuously by saliva and crevicular gingival fluid. Given that these bacteria can also utilize nitrogen compounds for their growth, it was hypothesized that nitrogenous compounds may influence their acid production; however, no previous studies have examined this topic. Therefore, the present study aimed to assess the effects of nitrogenous compounds (tryptone and glutamate) on glucose-derived acid production by Streptococcus and Actinomyces. Acid production was evaluated using a pH-stat method under anaerobic conditions, whereas the amounts of metabolic end-products were quantified using high performance liquid chromatography. Tryptone enhanced glucose-derived acid production by up to 2.68-fold, whereas glutamate enhanced Streptococcus species only. However, neither tryptone nor glutamate altered the end-product profiles, indicating that the nitrogenous compounds stimulate the whole metabolic pathways involving in acid production from glucose, but are not actively metabolized, nor do they alter metabolic pathways. These results suggest that nitrogenous compounds in the oral cavity promote acid production by Streptococcus and Actinomyces in vivo.
authors.affiliation: Division of Orthodontics and Dentofacial Orthopedics.|Division of Oral Ecology and Biochemistry, Tohoku University Graduate School of Dentistry, 4-1 Seiryo-machi, Aoba-ku, Sendai, 980-8575.
authors.forename: Yuka
authors.initials: Y
authors.lastname: Norimatsu
authors.affiliation: Division of Oral Ecology and Biochemistry, Tohoku University Graduate School of Dentistry, 4-1 Seiryo-machi, Aoba-ku, Sendai, 980-8575.|Division of Community Oral Health Science, Department of Community Medical Supports, Tohoku Medical Megabank Organization, Tohoku University, 2-1 Seiryo-machi, Aoba-ku, Sendai, 980-8573, Japan.
authors.forename: Junko
authors.initials: J
authors.lastname: Kawashima
authors.affiliation: Division of Orthodontics and Dentofacial Orthopedics.
authors.forename: Teruko
authors.initials: T
authors.lastname: Takano-Yamamoto
authors.affiliation: Division of Oral Ecology and Biochemistry, Tohoku University Graduate School of Dentistry, 4-1 Seiryo-machi, Aoba-ku, Sendai, 980-8575.
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Takahashi
mesh_terms: D000190:Actinomyces / Q000378:metabolism*; D000693:Anaerobiosis; D002264:Carboxylic Acids / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D005947:Glucose / Q000378:metabolism*; D018698:Glutamic Acid / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D009055:Mouth / Q000382:microbiology*; D010461:Peptones / Q000378:metabolism*; D013291:Streptococcus / Q000378:metabolism*
chemical_list: D002264:Carboxylic Acids; D010461:Peptones; D018698:Glutamic Acid; C001830:tryptones; D005947:Glucose
keywords: acids production; nitrogen compounds; oral Actinomyces; oral Streptococcus