Spontaneous Reaction Silencing in Metabolic Optimization
Figure 4
Probability distribution of the number of active reactions in nonzero-growth states that optimize typical objective functions.
The red solid lines indicate the corresponding number in the growth-maximizing state of Figure 2 (middle bar, red), and the red dashed lines indicate our estimates of the minimum number of reactions required for the organism to grow (Materials and Methods). [When the nonzero growth requirement is relaxed, a second sharp peak (not shown) arises, corresponding to a drop of ∼250 in the number of active reactions caused by the inactivation of the biomass reaction.]