TABLE 4.
Anabolic demand for intracellular metabolites in successive generations of a genealogy of lysine-producing C. glutamicum strains during lysine production phase
| Metabolite | Precursor demand (mmol mol of glucose−1)a
|
||||
|---|---|---|---|---|---|
| ATCC 13032 | ATCC 13287 | ATCC 21253 | ATCC 21526 | ATCC 21543 | |
| Glucose 6-phosphate | 12.43 ± 0.40 | 8.87 ± 0.23 | 8.08 ± 0.10 | 8.78 ± 0.10 | 8.48 ± 0.02 |
| Fructose 6-phosphate | 4.31 ± 0.14 | 3.07 ± 0.08 | 2.80 ± 0.04 | 3.04 ± 0.07 | 2.94 ± 0.01 |
| Pentose 5-phosphate | 53.31 ± 1.71 | 38.03 ± 0.97 | 34.63 ± 0.44 | 37.66 ± 0.92 | 36.35 ± 0.09 |
| Erythrose 4-phosphate | 16.25 ± 0.52 | 11.59 ± 0.30 | 10.56 ± 0.13 | 11.48 ± 0.28 | 11.08 ± 0.03 |
| Glyceraldehyde 3-phosphate | 7.82 ± 0.25 | 5.58 ± 0.14 | 5.08 ± 0.06 | 5.53 ± 0.14 | 5.33 ± 0.01 |
| 3-Phosphoglycerate | 78.42 ± 2.51 | 55.94 ± 1.42 | 50.94 ± 0.65 | 55.40 ± 1.35 | 53.47 ± 0.13 |
| Pyruvate/phosphoenolpyruvate | 120.88 ± 3.88 | 86.22 ± 2.19 | 78.52 ± 0.99 | 85.39 ± 2.09 | 82.42 ± 0.20 |
| α-Ketoglutarate | 103.71 ± 3.33 | 73.98 ± 1.88 | 67.37 ± 0.85 | 73.26 ± 1.79 | 70.71 ± 0.17 |
| Oxaloacetate | 54.83 ± 1.76 | 39.11 ± 1.00 | 35.62 ± 0.45 | 38.73 ± 0.95 | 37.38 ± 0.09 |
| Acetyl-CoA | 151.63 ± 4.86 | 108.16 ± 2.75 | 98.50 ± 1.25 | 107.11 ± 2.62 | 103.38 ± 0.25 |
| Diaminopimelateb | 8.86 ± 0.28 | 6.32 ± 0.16 | 5.75 ± 0.07 | 6.26 ± 0.15 | 6.04 ± 0.01 |
| Lysineb | 12.25 ± 0.39 | 8.74 ± 0.22 | 7.96 ± 0.10 | 8.65 ± 0.21 | 8.35 ± 0.02 |
Experimental data are given as mean values of two parallel incubations on (i) [1-13C]glucose and (ii) a 1:1 mixture of naturally labeled and [13C6]glucose with deviations between the two incubations. The estimation of precursor demands was based on the experimental biomass yield obtained for each strain (Table 1) and the biomass composition previously measured for C. glutamicum (6).
Diaminopimelate and lysine are regarded as separate anabolic precursors. This is due to the fact that anabolic fluxes from pyruvate and oxaloacetate into diaminopimelate (cell wall) and lysine (protein) contribute, in addition to the flux of lysine secretion, to the overall flux through the lysine biosynthetic pathway.