title: Characterization of Streptococcus salivarius growth and maintenance in artificial saliva.
abstract: OBJECTIVE
  To help gain a better understanding of factors influencing the establishment within the oral cavity of Streptococcus salivarius K12, a commensal oral bacterium, we characterized its behaviour in artificial saliva.
  
  
  RESULTS
  Streptococcus salivarius K12 was grown in artificial saliva complemented with a representative meal, under oral pH and temperature conditions. Exponential growth phase was characterized by a high specific growth rate (2.8 h(-1)). During maintenance phase, an uncoupling between growth and lactic acid production occurred, which allowed maintaining viability (95%), intracellular pH (6.6) and membrane polarisation (95%), and thus proton motive force. However, in late stationary phase, viability (64%) and vitality were degraded as a result of lower synthesis of energetic and glycogen-related proteins as compared to a richer medium.
  
  
  CONCLUSIONS
  Streptococcus salivarius was able to rapidly grow in complemented artificial saliva. Nevertheless, a degradation of its physiological state was observed in late-stationary phase.
  
  
  CONCLUSIONS
  This work demonstrates, for the first time, that artificial saliva was a convenient medium that permitted Strep. salivarius to grow in oral conditions (physico-chemical environment, addition of meals) but not to maintain cellular viability and vitality in starvation conditions.
authors.affiliation: AgroParisTech, INRA, UMR782, Thiverval-Grignon, France.
authors.forename: P
authors.initials: P
authors.lastname: Roger
authors.forename: J
authors.initials: J
authors.lastname: Delettre
authors.forename: M
authors.initials: M
authors.lastname: Bouix
authors.forename: C
authors.initials: C
authors.lastname: Béal
mesh_terms: D003470:Culture Media / Q000737:chemistry; D005285:Fermentation; D005434:Flow Cytometry; D005947:Glucose / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D019344:Lactic Acid / Q000032:analysis / Q000096:biosynthesis; D007785:Lactose / Q000032:analysis; D050296:Microbial Viability; D009055:Mouth / Q000382:microbiology*; D020543:Proteome / Q000032:analysis; D012464:Saliva, Artificial / Q000737:chemistry*; D013291:Streptococcus / Q000254:growth & development* / Q000378:metabolism; D013696:Temperature
chemical_list: D003470:Culture Media; D020543:Proteome; D012464:Saliva, Artificial; D019344:Lactic Acid; D005947:Glucose; D007785:Lactose