Figure 1.

Outline of PVD-mediated interactions and experimental setting. (a) Outline of the social interaction. Producers (blue) secrete pyoverdine (PVD, green) into the environment, where it binds iron (red). The resulting Fe-PVD complex is transported into the periplasm of both producers and non-producers. Iron is reduced and incorporated into cells, while PVD is transported back into the environment to scavenge additional ferric ions^44–46. (b) Metapopulation growth setting. We initiate a metapopulation by mixing producers and non-producers in random proportions and inoculating the individual populations, which grow independently. At given time points $\mathit{t}$, we take samples from each population, and merge them to determine the average population size and the global producer fraction of the metapopulation.