Before revision:  Here , we present a modeling framework combining the metabolic network and the enzyme production costs. A rigorous mathematical approximation by a timescale separation yields a coupled model of quasi steady state constraints on the metabolic reactions, and differential equations for the substrate concentrations and biomass composition. Based on this model, we propose a dynamic optimization approach to determine reaction fluxes, explicitly taking production costs for enzymes and enzymatic capacity into account .
After revision:  Here , we present a modeling framework combining the metabolic network with the dynamics of biomass production and composition, explicitly taking into account enzyme production costs and enzymatic capacity into account .