AIMS: 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. METHODS AND 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. SIGNIFICANCE AND IMPACT OF THE STUDY: 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.
AIMS: 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. METHODS AND 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. SIGNIFICANCE AND IMPACT OF THE STUDY: 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: Amber M Abram; Michelle M Szewczyk; Seon G Park; Sumita S Sam; Haya B Eldana; Fadi J Koria; Joseph M Ferracciolo; Laura A Young; Hina Qadir; Aaron J Bonham; Fei Yang; Jonathan S Zora; Sara A Abdulelah; Neil A Patel; Ayah Koleilat; Malaka A Saleh; Jamal A Alhabeil; Shameel Khan; Ashootosh Tripathi; John G Palanci; Eric S Krukonis Journal: Infect Immun Date: 2022-09-21 Impact factor: 3.609
Authors: Julius Laurens Rombouts; Elsemiek Madeleine Maria Kranendonk; Alberte Regueira; David Gregory Weissbrodt; Robbert Kleerebezem; Mark Cornelis Maria van Loosdrecht Journal: Biotechnol Bioeng Date: 2020-02-18 Impact factor: 4.530