Fig 6.

Confocal microscope images of biofilms formed with wild-type DL100 (A and D) and the short-isoform (pilA4) (B and E) and ΔpilA2 (C and F) strains on Fe(III) oxide-coated glass. The images were taken after 24 h in medium with 40 mM fumarate present (A, B, and C) and 4 days later after the fumarate was removed (D, E, and F). The scale bars represent 75 μm. (G) Average numbers of cells in biofilms of the isogenic DL100 (Wt) and short-isoform (pilA4) and ΔpilA2 strains formed on Fe(III) oxide-coated glass. Cell densities were measured after 24 h of incubation in the presence of 40 mM fumarate and 4 days later after the fumarate was removed. The results are the averages of six biological replicates from two independent experiments. The error bars are standard errors of the mean.