Fig. 2

Experimental values (filled dots) versus predicted FVA yields (floating bars) from A. succinogenes 130Z cultures on glucose (A and B) and xylose (C). Predicted minimum and maximum FVA yields for biomass, SA, AA, FA and EtOH (Y_x/S, Y_SA/S, Y_AA/S, Y_FA/S, Y_EtOH/S, respectively) were estimated while maintaining 95% of the maximum biomass formation (A1, B1 and C1). Similarly, minimum and maximum FVA yields between fermentative by-products (SA/AA, FA/AA and SA/FA) were estimated while maintaining 95% of the maximum biomass formation (A2, B2 and C2). In silico predictions were performed by setting the substrate uptake rate (q _S ) to the experimental value (except in condition C that was set to 8 mmol.gDCW^− 1.h^− 1). Experimental parameters for conditions A and B were obtained from batch cultures with defined medium (AM3) supplemented with 50 mM glucose and 150 mM NaHCO₃ under anaerobic conditions [32, 51]; while parameters for C were obtained from a continuous culture at a dilution rate of 0.05 h^− 1 under anaerobic conditions with supplemented medium (6 g.L^− 1 yeast extract, 10 g.L^− 1 corn steep liquor and 50–85 g.L^− 1 xylose). No biomass yield was experimentally determined for this condition [63]. Mass yields are given in g.g^− 1