Fig. 6

Plausible scenarios regarding the efficiencies of the two pathways: (i) Reduced yield and productivity (Flux_Glycolysis > Capacity_{Product-forming pathway}). (ii) Maximized yield, but reduced productivity due to glycolytic flux, which itself acts as a rate-limiting step (Flux_Glycolysis < Capacity_{Product-forming pathway}). Further improvement in productivity is restricted when the product-forming pathway exceeds the upper biological constraint (Flux_{Glycolysis, Max} < Capacity_{Product-forming pathway}). The faded region has never been explored. The red arrow indicates the optimized conditions for both glycolysis and the product-forming pathway (Balanced pathway, see “Discussion”)