Image: No EPS production (control)
Biofilm, aged 30,000 min (3 weeks). The contour lines show the oxygen concentration in mg/l. The image was rendered with POV-Ray, showing each cell as a sphere. The ammonia oxidisers ("Nitroso") are blue; the nitrite oxidisers ("Nitro") are red. See the reaction scheme below. The grey box at the bottom is the inert substratum. Note the wrapped around boundaries in the horizontal direction. Scale: total width of the system = 200 µm.
Without EPS production, the biofilm is dense throughout and oxygen penetration is very limited.
