Figure 4: Relation between the initial fructose concentration and the characteristic variables of hydrogen production in Synechocystis sp. strain PCC 6803-GT under the dark anaerobic nitrate-free condition. Characteristic variables are the initial hydrogen production rate (○), the number of moles of assimilated fructose per culture volume for 120 h (◎), the initial rate of fructose consumption that is observed from 0 h to 24 h (▲), the dry cell weight concentration at 120 h (◎), the initial endogenous glucose accumulation rate (□), the number of moles of assimilated endogenous glucose per culture volume from 24 to 120 h (▼) and the lactate concentration at 120 h (■).