Plots of biomass and product yields of all elementary flux modes for anaerobic 1,3-propanediol production. Each data point in a plot represents the biomass and propanediol yield for a calculated elementary flux mode that uses the respective electron transport model. Graph A, C and E utilize glucose as substrate under different electrical conditions. Graph B, D and F utilize glycerol as substrate under different electrical conditions. Text inserts in each graph summarize the corresponding substrate and product, electron transport model, number of computed elementary flux modes (efms) and maximum theoretical product yields (PY) with and without biomass (BM) production. no EET: no electrical enhancement, Cat1: cathodic electron supply coupled to energy conservation; Cat2: cathodic electron supply uncoupled to ATP formation.