Veillonella allows S. mutans to have continued ________.

Veillonella allows S. mutans to have continued ________.

• A. Metabolism
• B. Quorum sensing
• C. Biofilm formation
• D. Hydrogen peroxide production

Answer: (A)

The key idea here is metabolic cross-feeding in a dental biofilm. Veillonella uses the lactate produced by Streptococcus mutans, effectively removing this byproduct from the environment. Lactate buildup can inhibit further glycolytic metabolism in S. mutans, so when Veillonella consumes it, the inhibition is relieved and S. mutans can keep metabolizing sugars to generate energy. This interspecies interaction supports continued metabolism in S. mutans within the mixed-species community. Quorum sensing is about cell-to-cell signaling, not direct metabolic cross-feeding. Biofilm formation might be influenced by interspecies interactions, but the question specifically targets how metabolism is sustained. Hydrogen peroxide production is not the mechanism described here.

The key idea here is metabolic cross-feeding in a dental biofilm. Veillonella uses the lactate produced by Streptococcus mutans, effectively removing this byproduct from the environment. Lactate buildup can inhibit further glycolytic metabolism in S. mutans, so when Veillonella consumes it, the inhibition is relieved and S. mutans can keep metabolizing sugars to generate energy. This interspecies interaction supports continued metabolism in S. mutans within the mixed-species community.

Quorum sensing is about cell-to-cell signaling, not direct metabolic cross-feeding. Biofilm formation might be influenced by interspecies interactions, but the question specifically targets how metabolism is sustained. Hydrogen peroxide production is not the mechanism described here.