Surface topology affects wetting behavior of Bacillus subtilis biofilms

The wetting behavior of B. subtilis NCIB 3610 biofilms depends on the biofilm growth medium and on the location on the biofilm colony. When B. subtilis NCIB 3610 is grown on LB agar enriched with different molecules, the morphology of the formed macrocolonies changes a and a different wetting behavior of the biofilms is observed (b). In the images shown in a, the regions on the biofilm surface where the wetting tests were performed are marked with a closed and open red square, respectively. The droplet images shown in b were acquired on the peripheral regions of the biofilm colonies. For the peripheral regions of biofilms grown on MSgg agar, a pronounced contact angle hysteresis is observed, but not for biofilms grown on LBGM agar (c). The experimental time scale for the wetting/dewetting experiment was identical for both biofilm variants. Error bars denote the standard deviation. For data shown in b, n？≥？9; for data shown in c, n？=？