Figure 9: A model of the biofilm–planktonic life cycle, with dispersed cells as a unique intermediate between planktonic and biofilm lifestyles.

(1) The addition of dispersal agents can cause biofilm dispersal and release dispersed cells (shown in green). (2) Dispersed cells have lower expression levels of the Gac-dependent small RNAs RsmY and RsmZ, higher expression of T2SS and lower production of siderophores such as pyoverdine compared with planktonic cells (shown in brown). (3) Dispersed cells revert to the planktonic mode, which eventually colonize new surfaces and form biofilms.