Figure 3.

(A) Schematic illustration of a chemostat. (B) Photograph of a simple chemostat consisting of a glass flask with tubing for media delivery, aeration, and waste removal, and a magnetic bead for stirring the flask contents. (C) Example curves N(t), s(t) (black and green, respectively), obtained by numerical simulation of Eqs. (11) and (12) for γ = 1, K_s = 0.1, s₀ = 1, r_max = 2 and d = 1 (solid lines) and d = 3 (dashed lines). The simulations are initiated with N(0) = 0.5 and s(0) = 1 (in arbitrary concentration units). d_crit = 1.82 for this set of parameters. For the solid lines, d < d_crit and a stable bacterial population is maintained in the chemostat (the solid black line reaches a non-zero steady state); for the dashed lines, d > d_crit and the population is “washed out” (the dashed black line goes to zero).