Extracellular metabolite profiles of QS mutants grown under fermentative conditions. (A) Simplified view of glycolysis and pyruvate metabolism in V. cholerae. (B) Viability of LCD-locked (luxOD61E ΔaphA ΔhapR ΔvpsL; red solid triangles) and HCD-locked (ΔluxO ΔaphA ΔhapR ΔvpsL; blue solid squares) cells. Concentrations (millimolar) of formate (C), acetate, (D), lactate (E), acetoin (F), and 2,3-BD (G) in LCD-locked (red solid triangles) and HCD-locked (blue solid squares) mutants. P values (Student’s t test): *, P < 0.05; **, P < 0.01; ***, P < 0.001; ****, P < 0.0001. The values shown are averages of at least three replicates. Error bars denote the SEM.