Kind Discrimination and Competitive Exclusion Mediated by Contact-Dependent Growth Inhibition Systems Shape Biofilm Community Structure
Figure 7
Analysis of pillar structure formation throughout biofilm development.
CLSM and quantification of representative pillar structures in biofilms formed by BtE264, Bt-Bp1106a-1, Bt-Bp1106a-2, and BtΔbcpAIOB bacteria, each expressing gfp constitutively. A) Images in Ai) and Aii) represent examples of small and large, respectively, pillar structures formed by Bt-Bp chimeric strains, and represent typical pillar structures in both cases for BtE264 and BtΔbcpAIOB bacteria, at 24 hours post inoculation. Z stack image cross-sections are shown in the plane parallel to the glass coverslip (shown by large center image) at 6 µm above the substratum. Scale bar = 10 µm. For each of the strains in A), COMSTAT analysis of Z stacks collected after 24 hours of biofilm development were used to determine B) total biomass, C) average height, and D) maximum height of the biofilms. BtE264, purple bars; Bt-Bp1106a-1, orange bars; Bt-Bp1106a-2, red bars; and BtΔbcpAIOB, gray bars. Bars represent the mean of at least three independent experiments and error bars indicate the SEM. Significance was determined by two-tailed t-tests; * p<0.05, *** p<0.0001. E) and F) CLSM images of representative large pillar structures formed by the indicated strains at 48 and 72 hours, respectively, post inoculation. Z stack image cross-sections were taken at 6 µm (48 hours) or 10 µm (72 hours) above the substratum. Scale bar = 10 µm.