Mixed culture studies of Streptococcus mitis and oral enterococci.

Strains of Streptococcus mitis and oral enterococci were grown in mixed culture in 0.5% peptone, 1.0% peptone and 1.0% peptone supplemented with 0.5% glucose. In all three media the enterococci inhibited the S. mitis strains. The inhibition was strongest in the glucose supplemented broths, probably due to pH toxicity. Inhibition in the unsupplemented broths was not similarly caused, but no other inhibitory factors could be isolated from these culture.