TABLE 2.
Intracellular metabolite concentrations in the ΔpfkB strain during aerobic cultivation and subsequently oxygen-deprived organic acid production
| Metabolite or coenzyme ratio | Concn or ratio for the cells under indicated conditionsb |
|||
|---|---|---|---|---|
| Aerobic cultivation |
Oxygen deprivation |
|||
| Glucose | Fructose | Glucose | Fructose | |
| Metabolites (mM)a | ||||
| F1P | 0.79 ± 0.05 | 152.34 ± 12.52 | 2.78 ± 0.46 | 2.16 ± 0.16 |
| G6P | 5.96 ± 0.16 | 0.94 ± 0.07 | 1.99 ± 0.20 | 5.31 ± 0.62 |
| F6P | 3.59 ± 0.11 | 0.87 ± 0.11 | 1.12 ± 0.16 | 1.48 ± 0.14 |
| FBP | 14.30 ± 2.25 | 1.11 ± 0.04 | OD | OD |
| DHAP | 3.56 ± 0.19 | 3.86 ± 0.13 | 8.09 ± 1.26 | 9.64 ± 1.51 |
| GAP | 1.16 ± 0.21 | ND | 0.82 ± 0.09 | 1.08 ± 0.06 |
| BPG | 0.18 ± 0.03 | 0.16 ± 0.02 | 0.06 ± 0.01 | 0.05 ± 0.01 |
| 3PG + 2PG | 3.89 ± 0.14 | 3.21 ± 0.12 | 1.99 ± 0.20 | 1.63 ± 0.26 |
| PEP | 0.36 ± 0.02 | 0.86 ± 0.10 | 0.30 ± 0.05 | 0.21 ± 0.02 |
| Pyruvate | 35.28 ± 4.48 | 117.33 ± 24.87 | ND | 1.76 ± 0.16 |
| Ac-CoA | 0.12 ± 0.00 | 0.18 ± 0.01 | 0.04 ± 0.01 | 0.08 ± 0.01 |
| Cit + Icit | 3.14 ± 0.14 | 2.80 ± 0.20 | 0.46 ± 0.05 | 0.49 ± 0.08 |
| α-KG | 9.70 ± 0.51 | 22.63 ± 1.30 | 1.06 ± 1.83 | 2.64 ± 0.18 |
| Suc-CoA | 0.57 ± 0.04 | 1.32 ± 0.11 | 0.21 ± 0.06 | 0.32 ± 0.04 |
| Succinate | OD | OD | OD | OD |
| Fumarate | 2.12 ± 0.42 | 2.37 ± 0.48 | 0.32 ± 0.05 | 0.57 ± 0.05 |
| Malate | 8.85 ± 0.76 | 8.92 ± 0.77 | 1.42 ± 0.39 | 1.67 ± 0.08 |
| Oxaloacetate | 1.47 ± 0.15 | 2.18 ± 0.12 | 0.12 ± 0.02 | 0.04 ± 0.01 |
| Coenzyme ratios | ||||
| ATP/ADP | 3.69 ± 0.35 | 1.97 ± 0.13 | 1.93 ± 0.13 | 2.89 ± 0.13 |
| NADH/NAD+ | 0.05 ± 0.01 | 0.10 ± 0.02 | 1.03 ± 0.12 | 0.89 ± 0.10 |
F1P, fructose-1-phosphate; G6P, glucose-6-phosphate; F6P, fructose-6-phosphate; FBP, fructose-1,6-bisphosphate; DHAP, dihydroxyacetone phosphate; GAP, glyceraldehyde-3-phosphate; BPG, 1,3-bisphosphoglycerate; 3PG, 3-phosphoglycerate; 2PG, 2-phosphoglycerate; PEP, phosphoenolpyruvate; Ac-CoA, acetyl coenzyme A; Cit, citrate; Icit, isocitrate; α-KG, α-ketoglutarate; Suc CoA, succinyl-coenzyme A.
Aerobic cultivation, cells under aerobic conditions on A medium with glucose or fructose in the late exponential phase; oxygen deprivation, cells under oxygen deprivation conditions on BT-U medium with glucose after aerobic growth with glucose or fructose. The data are from five analytical replicates from one experiment. OD, overdose; ND, not detected.