Fig. 6. Predicting pairwise co-culture outcomes of diauxic laboratory E. coli strains.

a Schematic of pairwise invasion simulations. For each invasion event, a small amount of an invader strain was added into the monoculture of the resident strain. The system was then serially diluted until reaching a steady state. We simulated these pairwise invasions using E. coli strains discussed in ref. ⁴⁶, where their growth rates and yields were measured in experiments. An invader either replaces the resident, coexists with it, or is unable to invade. b Growth rates of the 13 laboratory E. coli strains on glucose (blue) and xylose (green), obtained from Barthe et al.⁴⁶. Note that one of the strains is anomalous. c Distribution of the initial lags (uniform between 0.5 and 1 h) and diauxic lags (uniform between 0 and 1 h) used in simulations. In each of 100 simulation runs, we randomly sampled the lag times of each strain, and performed exhaustive pairwise invasion simulations. d An example of competitive outcomes, showing 1 of the 100 runs. In most circumstances, the invader beats the resident (blue) or fails to invade (red). Coexistence (purple) or bistability can also occasionally happen. e Frequency of coexistence. A strain on the y-axis invades the monoculture of a strain on the x-axis, and the greyscale represents the frequency that both strains survive in the steady state among 100 runs where lag times were sampled.