Streptococcus salivarius is a lactose- and galactose-positive bacterium that is phylogenetically closely related to Streptococcus thermophilus, a bacterium that metabolizes lactose but not galactose. In this paper, we report a comparative characterization of the S. salivarius and S. thermophilus gal-lac gene clusters. The clusters have the same organization with the order galR (codes for a tran...

Pyruvate kinase of Streptococcus mutans JC 2 had an absolute and specific requirement for glucose-6-phosphate. Inorganic phosphate was a strong inhibitor. The enzyme required K+ or NH4+ and Mg2+ or Mn2+. S. mutans FIL and E 49, Streptococcus bovis ATCC 9809, and Streptococcus salivarius ATCC 13419 had also glucose-6-phosphate-dependent pyruvate kinases, whereas Streptococcus sanguis NCTC 10904 ...

Bacteriocin-producing probiotic Streptococcus salivarius M18 offers beneficial modulatory capabilities within the oral microbiome, apparently through potent inhibitory activity against potentially deleterious bacteria, such as Streptococcus pyogenes. The oral cavity persistence of S. salivarius M18 was investigated in 75 subjects receiving four different doses for 28 days. Sixty per cent of the...

This study examined salivary flow and salivary pH and the prevalence and levels of cariogenic bacteria in the saliva of oncological patients and healthy controls. Quantitative real-time polymerase chain reaction was used to assess the levels of microbes including Streptococcus mutans, Streptococcus sobrinus, Lactobacillus salivarius, and Lactobacillus acidophilus in the saliva of 41 patients wi...

Streptococcus thermophilus is unable to metabolize the galactose moiety of lactose. In this paper, we show that a transformant of S. thermophilus SMQ-301 expressing Streptococcus salivarius galK and galM was able to grow on galactose and expelled at least twofold less galactose into the medium during growth on lactose.

Objective: To evaluate the anticariogenic effect of dandelion extract against different oral pathogenic clinical isolates. Methods: In the present study, we evaluated the antimicrobial effect of dandelion against oral pathogens by the minimum inhibitory concentration and minimum bactericidal concentration. Clinical isolates such as Enterococcus faecalis, Streptococcus mutans, Streptococcus sali...

Galactokinase and beta-galactosidase-deficient strains of Streptococcus salivarius were constructed to define the pathways for lactose and galactose catabolism. It was found that S. salivarius does not possess a lactose-specific phosphoenolpyruvate phosphotransferase system (PTS), that intracellular lactose was hydrolyzed by beta-galactosidase, and that galactose is catabolized exclusively thro...

The human small-intestinal microbiota is characterised by relatively large and dynamic Streptococcus populations. In this study, genome sequences of small-intestinal streptococci from S. mitis, S. bovis, and S. salivarius species-groups were determined and compared with those from 58 Streptococcus strains in public databases. The Streptococcus pangenome consists of 12,403 orthologous groups of ...