Figure 3.

Overview of the effects of H₂O₂ production on oral biofilm development. Initially, the antagonistic effect of streptococcal H₂O₂ production was described. As a consequence, competitors are eliminated, and the integration of H₂O₂ compatible species into the developing biofilm is promoted. H₂O₂ production also causes the release of DNA into the environment. The extracellular DNA promotes biofilm formation and cell-cell aggregation. In addition, H₂O₂ causes DNA damage, which in turn could lead to beneficial mutations in competent oral streptococci uptake of extracellular DNA. Extracellular DNA could therefore support adaptational processes to changing environmental conditions and promote evolution of oral biofilm development.