Type and capacity of glucose transport influences succinate yield in two-stage cultivations

Table 3 Strain performance in the second, anaerobic phase of two-stage cultivations

Strain	µ [1/h]	Glc_Up [mM/(g*h)]	Y_Suc [mol/mol_Glc]	Y_For [mol/mol_Glc]	Y_Pyr [mol/mol_Glc]	Prod_Suc [mM/(g*h)]
MG1655	0.37 ± 0.011	9.07 ± 0.94	0.29 ± 0.02	0.28 ± 0.03	nd	2.62 ± 0.18
KBM151101	− 0.013 ± 0.002	0.15 ± 0.03	0.10 ± 0.05	0.12 ± 0.16	0.07 ± 0.05	0.02 ± 0.01
SB2	0.011 ± 0.001	1.10 ± 0.19	1.24 ± 0.01	0.38 ± 0.02	nd	1.29 ± 0.25
SB2/pPckA	0.004 ± 0.001	0.59±0.13	1.42 ± 0.03	0.38 ± 0.01	nd	0.83 ± 0.18
SB2/pEcPpc	− 0.012 ± 0.002	0.23 ± 0.07	1.08 ± 0.08	0.11 ± 0.03	0.05 ± 0.01	0.25 ± 0.08
KBM1673	− 0.003 ± 0.000	0.64 ± 0.10	0.83 ± 0.04	0.47 ± 0.01	0.22 ± 0.02	0.53 ± 0.08
KBM1673/pPckA	0.068 ± 0.002	2.68 ± 0.12	0.92 ± 0.01	0.25 ± 0.01	0.35 ± 0.02	2.76 ± 0.10
KBM1673/pEcPpc	− 0.007 ± 0.001	0.18 ± 0.05	1.05 ± 0.10	0.37 ± 0.03	0.06 ± 0.02	0.19 ± 0.05

All data refer to the second, anaerobic phase of two-stage cultivations. µ denotes the growth rate in doublings per hour. Negative values for µ result from decreasing OD₄₂₀ over time which is most probably related to cell death. Glc_Up denotes the specific glucose uptake rate and Prod_Suc denotes the succinate productivity. g means g dry cell weight. The yields Y_Suc, Y_For, Y_Pyr stand for the moles succinate, formate and pyruvate respectively, produced per mole of glucose consumed. Errors indicated refer to SD. Reduction of biomass in some strains results in a negative growth rate. Glucose uptake and succinate productivity were calculated by weighted linear least squares. All results are the average of at least three independent biological repeats with exception of MG1655 with only two replicates. nd means that the product could not be detected