Figure 2.

Diagrammatic representation of the tower- and mushroom-like micro-colonies that constitute the structural elements of biofilms. Sessile cells constitute only approximately 15% of the volume of their matrix-enclosed communities, so the micro-colonies are viscoelastic and deformable in high shear. Well-developed water channels conduct water in convective flow and deliver nutrients to most parts of the community. Figure is reproduced with permission from the American Society for Microbiology (60).