Comparisons between phenotypic phase planes (PhPP) calculated using iJR904 and iJE660a. (a-e) The PhPP for growth on (a) malate, (b) glucose, (c) acetate, (d) glycerol, and (e) α-ketoglutarate (αKG) are shown, where the red lines show the PhPP calculated from iJR904 and the blue lines the PhPP calculated from iJE660a. The line of optimality (LO) corresponds to maximal biomass yield. (e) With αKG as the carbon source, the phase planes calculated from iJR904 (red line) and iJE660a (blue line) are drastically different in the oxygen-limited region (area below the LO). (f) The different metabolic routes (along with their associated genes) added to the network in iJR904 that enable fermentative growth on αKG are shown in red, blue and green. AC, acetate; CIT, citrate; GLYCLT, glycolate; GLYC-R, R-glycerate; GLX, glyoxylate; ICIT, isocitrate; αKG, α-ketoglutarate, OAA, oxaloacetate; 3PG, 3-phospho-D-glycerate; SUCC, succinate; SUCCOA, succinyl-CoA.