“…Thereafter, while the biofilm continues to grow, planktonic cells rapidly decrease in number, and eventually the entire planktonic cell population integrates into the biofilm. Interestingly, freshly recruited planktonic cells are mainly located in specific areas of the biofilm, where few sessile cells are originally present, suggesting spatial heterogeneity between the two populations [ 85 ]. In the case of floating biofilms of B. thuringiensis , two main structures have been described (ring and pellicle).…”