Ned S. Wingreen
April 5, 2016
Bacterial cartels at steady supply
Metagenomics has revealed hundreds to thousands of bacterial species coexisting in almost all microbiota. In a few well-studied cases, bacterial communities have been observed to coordinate their collective metabolism. To better understand this collective behavior, we physically model the population dynamics of bacteria that compete for steadily supplied resources. Importantly, we explicitly model the metabolic fluxes yielding cellular biomass production. We find that population dynamics generally leads to the coexistence of different metabolic types, which satisfy an extended competitive exclusion principle. Moreover, we establish that these consortia of metabolic types act as cartels, whereby population dynamics pins down resource concentrations at values for which no other strategy can invade. Strikingly, these cartels also yield maximum biomass, constituting a microbial example of Adam Smith's ``invisible hand" leading to collective optimal usage of resources.