FIG. 1.

Comparison of the atomized mineral oil droplets deposited on agar plates around a growing colony of E. coli DH5α that does not produce biosurfactant (A, E, and I), a growing colony of P. syringae B728a that produces biosurfactant (B, F, and J), Silwet L-77 at a 500-fold dilution (C, G, and K), and Tween 20 at a 5-fold dilution (D, H, and L). (A to D) Overviews of halos seen with this assay. Bars represent 1 cm. (E to G) Microscopic closeups of the oil droplets observed within the halos viewed from the top. (H to L) Droplets viewed from the side. Bars represent 0.2 mm for microscopic images in E to L.