title: The effects of tetradecyl-4-ethyl-pyridinium chloride on the maximum specific growth rate biomass and hydrolytic enzyme production of Bacteroides gingivalis in continuous culture.
abstract: Bacteroides gingivalis was grown in continuous culture in the presence of tetradecyl-4-ethyl-pyridinium chloride (TDEPC). The maximum specific growth rate and biomass levels decreased with increasing concentrations of antimicrobial and complete inhibition of growth occurred when the TDEPC concentration reached 40 mg/l. Hydrolytic enzymes were detected in cells, vesicles and supernatant fractions of whole culture. Levels of alkaline phosphatase initially increased with increasing concentrations of TDEPC, but at higher concentrations (15-20 mg/l) of antimicrobial decreased significantly to less than 20% of the control value. The levels of N-acetyl-beta-glucosaminidase remained approximately constant at lower concentrations of TDEPC (0 10 mg/l) but then decreased significantly at higher concentrations. In contrast, levels of trypsin-like protease were reduced significantly at even low concentrations of TDEPC (5 10 mg/l) and decreased further as the TDEPC concentration increased. Therefore, TDEPC exerts significant physiological effects on B. gingivalis at concentrations below those considered to be lethal to the cell.
authors.affiliation: Department of Science, Bristol Polytechnic, Frenchay, UK.
authors.forename: J
authors.initials: J
authors.lastname: Greenman
authors.forename: T
authors.initials: T
authors.lastname: Minhas
mesh_terms: D000118:Acetylglucosaminidase / Q000378:metabolism; D000469:Alkaline Phosphatase / Q000378:metabolism; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001439:Bacteroides / Q000187:drug effects / Q000201:enzymology* / Q000254:growth & development; D003470:Culture Media; D011726:Pyridinium Compounds / Q000494:pharmacology*; D012044:Regression Analysis; D014357:Trypsin / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D003470:Culture Media; D011726:Pyridinium Compounds; C068030:tetradecyl-4-ethylpyridinium; D000469:Alkaline Phosphatase; D000118:Acetylglucosaminidase; D014357:Trypsin