FIG 8.

Scheme of the dual-species P. aeruginosa and E. faecalis biofilm development. (A) P. aeruginosa and E. faecalis attach to a surface without spatial separation. (B) During the early stages of dual-species biofilm formation, the attached cells proliferate and start producing EPS, Pel (blue straight line), and Psl (purple curved line). (C) P. aeruginosa and E. faecalis start to exhibit distinct spatial distributions. (D) In the maturation stage of the dual-species biofilm, P. aeruginosa forms a structured biofilm on top of the E. faecalis biofilm: Psl is associated with the surface and between P. aeruginosa, while Pel is associated with interspecies interactions between P. aeruginosa and E. faecalis.