Fig. 1
Heat map of the 8-dimensional Pareto front from MOFA analysis (objectives: growth, carbon fixation/carbon efficiency, nutrient allocation, ATP production, production of some small organic byproduct (pyruvate, succinate and α-ketoglutarate), and H2 production) of anaerobic mixotrophic metabolism of acetate in R. palustris. a 1719 unique Pareto-optimal solutions identified during our analysis. b Select Pareto-optimal solutions from same MOFA study are highlighted for discussion. Each biological objective was examined at intervals equaling 1/10 maximum normalized value. The analyses showed that the observed growth rate (E) is smaller than the maximum theoretical growth rate (A) in a carbon-limited system with unlimited light absorbing capability. When CO2 export was constrained with experimental measurements (without limiting light) the predicted growth rate was still larger than the measured value (B). Eliminating CBB (with unlimited light) resulted in increased production of CO2, but the predicted growth rate was still greater than the measured value (C). Limiting light and carbon import brought the predicted growth rate closer to measured value (D), however the rate of CO2 export was greater than measured value. When light, acetate import, and CO2 export were limited the model predicted that succinate will be exported. Blocking export of succinate slightly lowered the growth rate and resulted in production of other small organic acids (F). Finally, the simulations showed that H2 production competes with growth pathways for resources and that maximum theoretical H2 production (G) would result in cessation of growth. This result is supported by experimental observations [61]