Fig. 5: Temporal resource separation can prevent invasion and community collapse by a dual auxotroph cheater.

a Two E. coli single amino acid auxotrophs exhibit mutually beneficial cross-feeding. A third community member having both amino acid auxotrophies consumes both exchanged resources but does not participate in their production. Introduction of the cheater to the cross-feeding resident community has three possible outcomes: (1) collapse of the entire community, (2) coexistence of the cheater and resident community, and (3) exclusion of the cheater by the resident community. b, c Simulations of the resident community at steady state are perturbed at \(t=0\) by introduction of the cheater. The initial abundance of the cheater was set at 0.05 in the stable equilibrium case and 0.5 in the oscillatory case. d, e Amino acid concentrations in the stable equilibrium and oscillating communities. f, g Specific growth rates of the community members in the stable equilibrium and oscillating communities. The dilution rate through the chemostat is shown as a black dashed line to highlight the periods during which each community member shows a net positive growth rate.