Figure 3.

Simulating a syntrophic batch co-culture. Propionate is utilized by S. fumaroxidans and converted to acetate, CO₂, and H₂. M. hungatei then converts CO₂ and H₂ to CH₄. Both Matlab's ode15s ODE solver (lines) and μbialSim's augmented forward Euler method (symbols, every 15th data point is plotted) lead to similar results. As H₂ is faster consumed than produced, the time step size gets frequently reduced, most notably just prior to the depletion of propionate after which growth of both populations ceases.