Fig 1.

Chemotaxis of P. aeruginosa PAO1 toward potential chemoeffectors. Accumulation of bacteria (WT-Washington) in capillaries containing 1 mM of the indicated chemical compound in the chemotaxis buffer, except guanine that was used at 10 µM due to poor solubility. As indicated by dashed lines and colors, we defined compounds that attract ≥30,000 cells per capillary as strong chemoattractants (shown in orange); 10,000–30,000 cells per capillary as medium chemoattractants (shown in dark-gray) and <10,000 cells per capillary as weak chemoattractants (shown in light-gray). All data have been corrected by the number (7,825 ± 623) of bacteria in buffer-containing capillaries. The means and standard deviations of four biological replicates each conducted in triplicate are shown. Error bars indicate the mean ± standard deviations. Significance of difference from buffer-containing capillaries, assessed using an unpaired Student’s t-test, is indicated by asterisks (ns: nonsignificant, *P ≤ 0.05, **P ≤ 0.01, ***P ≤ 0.001, and ****P ≤ 0.0001).