Table 1.

Stoichiometric equations and standard reaction entropies of the remaining elementary modes in AS411. All remaining biomass-producing modes have cell growth and ethanol production coupled. The 42 elementary modes can be grouped into 4 families of modes that have the same overall reaction stoichiometry.

Family	Reaction stoichiometry	No. of EMs	YETOH1	YBIO1	ΔS2
Xylose substrate
1	Xylose → 1.67 Ethanol + 1.67 CO2+ 1.67 ATP	3	0.51	0	0.363
2	Xylose → 1.67 Ethanol + 1.67 CO2	15	0.51	0	0.327
3	Xylose + 0.59 NH3 → 2.40 Biomass + 0.09 H2 +0.92 Ethanol + 0.98 CO2	18	0.28	0.41	0.302
4	Xylose + 0.59 NH3 → 2.40 Biomass + 0.09 Formate + 0.92 Ethanol + 0.89 CO2	6	0.28	0.41	0.285
Glucose substrate
1	Glucose → 2 Ethanol + 2 CO2+ 2 ATP	3	0.51	0	0.547
2	Glucose → 2 Ethanol + 2 CO2	15	0.51	0	0.503
3	Glucose + 0.70 NH3 → 2.88 Biomass + 0.11 H2+ 1.10 Ethanol + 1.18 CO2	18	0.28	0.41	0.473
4	Glucose + 0.70 NH3 → 2.88 Biomass + 0.11 Formate + 1.10 Ethanol + 1.07 CO2	6	0.28	0.41	0.453

¹Yield is shown in g-product produced per g-sugar consumed.

²The standard entropy of reaction per mole glucose of each family (kJ/K-mole) is calculated using Gibbs equation and correlations with the degree of reduction given in Sandler and Orbey (1991).