Determination of the Thermodynamically Dominant Metabolic Pathways

An effective strategy comprising two phases is proposed
to determine
the thermodynamically dominant pathways in a metabolic network of
a given phenotype, involving several metabolic reactions. In the first
phase, stoichiometrically feasible metabolic pathways are exhaustively
identified through the flux balance analysis and the graph-theoretic
method based on P-graphs. In the second phase, thermodynamically dominant
pathways are selected from these stoichiometrically feasible metabolic
pathways on the basis of the Gibbs free energy change of reaction.
The proposed strategy’s efficacy is demonstrated by applying
it to two E. coli models: one is for maximal acetate
and ethanol production, and the other is for maximal poly­(3-hydroxybutyrate)
production.