Figure 1.

Bacterial extinction during experimental evolution. Bacteriocin-sensitive bacteria (O:9) were grown in the presence of a bacteriocin producer (PAO1) in either iron-limited or -rich media. Bacteriocin-sensitive bacteria (O:9) were isolated after each round of growth and passaged to fresh media containing new cultures of the bacteriocin producer (PAO1). Significantly more bacteriocin-sensitive populations went extinct under iron-limited conditions compared with when iron was present in the environment after circa 70 bacterial generations (that is, 10 transfers).