Figure 4.

The biofilm community is initially competitive but evolves to become synergistic. (A) Productivity (CFU/mL) of the evolved biofilm community (observed) was quantified using clones representing the dominant members of the population at the Early and Late time points. The Late community is significantly more productive than expected (t = 25.25, df = 12, P < 0.0001). (B). Effect of swapping the Early and Late S clones between these communities. Mixtures of Late and Early ecotypes were significantly less productive than the Late community (Late S, Early RW: t = 4.57, df = 4, P < 0.01; Early S, Late RW: t = 3.91, df = 4, P < 0.02). Expected productivity in mixture (expected) was calculated using observed monoculture yield after 24 h multiplied by the starting proportion of the ecotypes in the mixed population. Results were analyzed using log₁₀ transformed data, a one-way ANOVA, and Tukey's HSD post hoc tests (P < 0.05). Error bars are 95% confidence intervals (df = 3).