Fig. 3.

Replacement series analysis of mixed biofilms after 96 h. (A) Observed biovolume of 30-84red (gray bars), 30-84ZNgreen (open bar), and total biofilm (both bars). The dashed line indicates the expected biovolume of strain 30-84 in mixed biofilms predicted from the performance of 30-84 without 30-84ZN (given a 50% or 100% reduction in inoculum). Wild-type strain 30-84 achieved a lower biovolume in the presence of 30-84ZN than would be predicted by its performance without 30-84ZN, indicating that the wild type was negatively impacted by the presence of 30-84ZN. 30-84ZN was unable to form a biofilm without the wild type, but it formed a mixed biofilm with the wild type. (B) Expected (dashed lines) and observed (gray bars) biovolumes of 30-84red, 30-84GacAgreen (open bar), and total biofilm (both bars). The wild type reached a higher biovolume in the mixture with 30-84GacA than expected based on its performance without 30-84GacA. 30-84GacA was unable to form a biofilm without the wild type, but it formed an extensive chimeric biofilm with the wild type. The total population of the mixed biofilm significantly exceeded the population of the wild type alone. Error bars denote standard errors.