1. N-acyl homoserine lactone (AHL) activity was detected in an in vitro dental plaque community under 5% carbon dioxide but not anaerobic conditions.
2. AHL-degrading lactonases reduced quorum sensing activity and biofilm biomass under 5% carbon dioxide.
3. Disrupting AHL signaling altered microbial community composition in carbon dioxide–grown biofilms.
4. Biofilm metabolic output, including lactate production, changed following AHL manipulation.
5. Exogenous AHLs altered community structure in anaerobic cultures despite absent endogenous AHL activity.

Source: npj: biofilms and microbiomes