Fig 5.

Quantitative analysis of the chemotactic response of PAO1 to 2 mM catechol (open bars) and 1 mM 4CA (solid bars) in the presence of different P_i concentrations in the chemotaxis buffer using a computer-assisted capillary assay. Cells grown overnight in 2× YT medium were cultured in T₀ or T₅ medium, as indicated in the text, and then resuspended in the chemotaxis buffer with various concentrations of P_i (KH₂PO₄). The strength of the chemotactic attraction was determined by the increase in the cell number in the analysis frame area at t₆₀ (60-s exposure) normalized to that at t₀ (N_t60/N_t0). Data are shown as the mean ± SD and are derived from at least three independent experiments conducted in triplicate.