Acid-induced acid tolerance and acidogenicity of non-mutans streptococci

N. Takahashi, T. Yamada

研究成果: Article査読

61 被引用数 (Scopus)


Acid tolerance and acidogenicity of non-mutans streptococci and their capacity of acid adaptation were studied. The cells of non-mutans streptococci (Streptococcus sanguis [Streptococcus sanguinis], Streptococcus gordonii, Streptococcus oralis and Streptococcus mitis) grown at pH 7.0 showed 0.0088% to 71% viability after acidification at pH 4.0 for 60 min, whereas the cells of mutans streptococci (Streptococcus mutans) were not killed by the acidification. Washed cells of non-mutans streptococci lowered pH to 4.04-4.33 in the presence of glucose, while mutans streptococci cells lowered pH to 3.70. When the growth pH was shifted to 5.5 for 30-90 min, the viability of non-mutans streptococci after the acidification at pH 4.0 for 60 min increased (0.25% to 91%) and the minimum pH values of the cells in the presence of glucose decreased (3.90-4.19). Along with the increase in acid tolerance and acidogenicity, non-mutans streptococci increased activities of H+-ATPase and arginine deiminase and amounts of stress proteins cross-reacting with 60 kDa and 70 kDa heat shock proteins (Hsp60 and Hsp70). These results indicate that non-mutans streptococci were capable of increasing their acid tolerance and acidogenicity in response to environmental acidification. Furthermore, it is suggested that the acid adaptation observed in non-mutans streptococci cells could involve the induction of H+-ATPase, arginine deiminase and stress protein syntheses. The strains of non-mutans streptococci, which are pioneer bacteria for dental plaque formation and predominant in plaque microbial flora, may play a significant role in shifting the dental plaque environment toward acidic and consequently promoting the colonization of more acid-tolerant and acidogenic bacteria such as mutans streptococci and lactobacilli.

ジャーナルOral Microbiology and Immunology
出版ステータスPublished - 1999 2月

ASJC Scopus subject areas

  • 微生物学
  • 免疫学
  • 歯科学(全般)
  • 微生物学(医療)


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