Fig. 2.
Biofuel production without export. a Cells produce intracellular biofuel b i, which inhibits their growth, and consequently limits biofuel production. b Experimental growth curves (dots and error bars) are fit to the model in Eq. 1 to estimate the model parameters αn and δn (model fits shown as solid lines). The amount of butanol added to the culture is indicated in the figure, where experimental data is for exogenously added butanol in cells without intracellular butanol production. c Simulation of cell growth and biofuel production. Growth inhibition occurs when biofuel produced by the cells reaches toxic levels. Simulation parameters are αn = 0.66 1/h, δn = 0.91 1/M h, and αb = 0.1 1/h