TABLE 2.

Effect of AI-2 on the biofilm formation of E. coli ATCC 25404, DH5α, and MG1655 in LB medium and 96-well platesa

E. coli strainAI-2 (μM)Total biofilm (OD540)Fold change
ATCC 2540400.05 ± 0.021
0.20.46.8 ± 0.9
3.21.0 ± 0.217.4 ± 0.7
111.5 ± 0.426 ± 2
DH5α00.01 ± 0.051
0.20.05 ± 0.023.9 ± 0.6
3.20.3 ± 0.325.0 ± 0.9
110.4 ± 0.228.9 ± 0.3
MG165500.41 ± 0.021
0.20.5 ± 0.11.2 ± 0.5
3.21.0 ± 0.12.5 ± 0.3
111.6 ± 0.54 ± 2
  • a Biomass measured at 24 h. Each experiment was performed twice, and one standard deviation is shown.