Pseudomonas aeruginosa Promotes Escherichia coli Biofilm Formation in Nutrient-Limited Medium
Figure 5
Colonization of P. aeruginosa biofilms by E. coli under a controlled flow gradient in a planar flow cell and in R2A medium.
E. coli appears red and P. aeruginosa appears green. Results are presented for two local fluid velocities, 0.96 mm/s (top row) and 1.69 mm/s (bottom row). Column A) E. coli deposited on 3-day old P. aeruginosa biofilms (grid unit is 23.8 µm). B) Mixed P. aerugiosa and E. coli biofilms on day 6, 3 days after E. coli inoculation (grid unit in B is 23.8 µm). C) Horizontal section near the base of the biofilm and vertical sections of the biofilm shown in panel B (scale bar = 15 µm). D) Distribution of P. aerugiosa and E. coli biomass as function of height, indicating that E. coli was the dominant species throughout the biofilm. E. coli appears red and P. aeruginosa-GFP appears green.