title: [Influence of glucose concentration on the inhibition of Streptococcus oligofermentans on Streptococcus mutans].
abstract: OBJECTIVE
  To investigate the inhibition of Streptococcus oligofermentans (So) on Streptococcus mutans (Sm) and the producibility of hydrogen peroxide by So under the influence of glucose concentration environment.
  
  
  METHODS
  The inhibition between So and Sm was observed by plating method under the different glucose concentration environment. The initial synthesis rates and production of hydrogen peroxide by So were determined under the different glucose concentration environment by 4-aminoantipyine-horseradish peroxidase method at A(510).
  
  
  RESULTS
  Under 0, 10 and 50 mmol/L glucose environment, the inhibition of So on Sm was evident. When both Sm and So were inoculated at the same time, the ratio of inhibition area by bacterial membrane area was 0.202 ± 0.005, 0.467 ± 0.025, 0.468 ± 0.028 under 0, 10, 50 mmol/L glucose environment. When So was cultivated first and then Sm applied, the ratio was 0.394 ± 0.004, 0.811 ± 0.075 and 0.816 ± 0.007 under 0, 10 and 50 mmol/L glucose environment respectively. The inhibition under 10 and 50 mmol/L glucose environment were more significant than that under non-glucose environment. There was no significant difference between these two glucose concentrations (P > 0.05). The initial synthesis rates of H2O2 by So under the 10 mmol/L [(23.573 ± 0.263) µmo×L(-1)×min(-1)] and 50 mmol/L [(23.337 ± 0.473) µmol×L(-1)×min(-1)] glucose were higher than without glucose[(10.513 ± 0.516) µmol×L(-1)×min(-1)], P < 0.05. H2O2 was not detected in 1000 mmol/L glucose. However, the production of H2O2 by So under 0 mmol/L glucose was higher than other glucose concentrations (P < 0.05).
  
  
  CONCLUSIONS
  The capability of the inhibition of So on Sm was affected by glucose environment and was much stronger under certain glucose concentrations (10, 50 mmol/L).
authors.affiliation: Department of Endodontics, Stomatological Hospital, Tianjin Medical University, China. zbwlg5647@sina.com
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
authors.forename: Fei
authors.initials: F
authors.lastname: Wu
authors.forename: Lei
authors.initials: L
authors.lastname: Chu
authors.forename: Ke-ke
authors.initials: KK
authors.lastname: Xia
authors.forename: Ying-hui
authors.initials: YH
authors.lastname: Wang
authors.forename: Li-geng
authors.initials: LG
authors.lastname: Wu
mesh_terms: D000898:Antibiosis; D004305:Dose-Response Relationship, Drug; D005947:Glucose / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000378:metabolism; D013291:Streptococcus / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D013295:Streptococcus mutans / Q000254:growth & development* / Q000378:metabolism
chemical_list: D006861:Hydrogen Peroxide; D005947:Glucose