Figure 3.

Relative composition of the species within the biofilm. S. mutans cells were grown with or without B. subtilis in BHI supplemented with 3% lactose with various concentrations of the casein proteins (0%, 0.5%, 1%, or 1.5%). After 24 h of incubation at 37 °C in 95% air/5% CO₂, the formed biofilms were washed twice. The DNA extraction was conducted using NaOH and real-time qPCR based on the species-specific 16S ribosomal RNA (rRNA) primers to quantify the amount of each bacterium. The data display the mean ± SD of four biological repeats, each performed in triplicate. * p < 0.05 compared to control (0% casein).