Image: Capsule formation by ammonia oxidisers at a low rate
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, and the capsules surrounding them are bluish (cyan); 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.
As with EPS production at a low rate, no death occurs since cells don't waste too much energy on capsule formation. Cells here are very evenly spaced and just not that dense as without EPS production or capsule formation.
