FIG. 1.

(Left) Image of the trajectories (green) of E. coli (4-h growth time) swimming in the air-TN interfaces superimposed on the last frame of one acquisition (bacteria in white). Motion orientation of three highlighted trajectories is indicated by arrows, and values of instantaneous curvature (κ_i) are color coded. (Right) κ_i image of the trajectories of three consecutive acquisitions. CCW, red (κ_i <−0.007 μm⁻¹); linear, yellow (−0.007 μm⁻¹ < κ_i < 0.007 μm⁻¹); CW, blue (0.007 μm⁻¹ < κ_i). Bar, 35 μm.