Figure 2. 5-Methylindole exhibited bactericidal activity against Gram-negative bacteria in stationary-phase.

Survival of different Gram-negative bacteria in stationary-phase following a 3-h treatment with indole, 2-methylindole or 5-methylindole at increasing concentrations (0, 1, 2, 3, 4, 5, 6, 7 and 8 mM). Data represent the means ± SD of three replicates of one independent experiment. An asterisk (*) represents no detectable colonies on LB dish when 5 μL treated cells were spot plated.