Table 5.
Statistical evaluation of metabolic fluxes of Saccharomyces cerevisiae cultured in chemostat under aerobic, glucose-limited conditions at μ = 0.15 h-1, μ = 0.30 h-1, and μ = 0.40 h -1.
| Flux Parameter | Interval for 90 % Confidencea (μ = 0.15 h-1) | Interval for 90 % Confidence (μ = 0.30 h-1) | Interval for 90 % Confidence (μ = 0.40 h-1) |
| Net Flux | |||
| glucose 6-phosphate isomerase | [24.7 26.1] | [58.5 61.3] | [77.3 78.9] |
| fructose 1,6-bisphosphate aldolase | [59.5 61.0] | [77.6 79.6] | [86.3 88.0] |
| triosephosphate isomerase | [57.6 59.1] | [72.1 74.1] | [79.6 81.6] |
| glyceraldehyde 3-phosphate dehydrogenase | [132.5 135.9] | [157.7 162.0] | [169.2 173.2] |
| enolase | [126.9 130.7] | [154.1 158.8] | [165.2 169.9] |
| pyruvate kinase | [122.4 126.5] | [150.6 155.8] | [162.2 167.4] |
| glucose 6-phosphate dehydrogenase | [53.7 55.4] | [28.1 31.2] | [14.5 15.5] |
| transaldolase | [18.3 18.9] | [9.7 10.7] | [5.1 5.4] |
| transketolase 1 | [18.3 18.9] | [9.7 10.7] | [5.1 5.4] |
| transketolase 2 | [15.9 16.6] | [7.9 9.1] | [3.6 4.0] |
| pyruvate carboxylase | [21.6 27.0] | [24.5 30.3] | [25.5 37.3] |
| pyruvate decarboxylase | [60.5 83.8] | [74.4 92.6] | [120.9 126.4] |
| acetyl CoA synthase | [60.9 84.1] | [10.9 29.3] | [8.5 14.2] |
| intercompartmental pyruvate transport | [17.8 38.1] | [33.7 51.0] | [7.5 11.2] |
| intercompartmental oxaloacetate transport | [14.4 19.9] | [18.3 24.9] | [20.8 33.5] |
| intercompartmental acetyl CoA transport | [41.0 63.6] | [0.0 15.4] | [0.0 2.8] |
| overall intercompartmental transport | [94.3 100.1] | [65.6 75.7] | [33.2 41.2] |
| pyruvate dehydrogenase | [9.8 36.5] | [36.2 61.9] | [16.3 31.2] |
| citrate synthase | [69.3 77.4] | [48.8 60.2] | [17.2 29.4] |
| oxoglutarate dehydrogenase | [59.2 68.1] | [41.0 53.7] | [10.4 23.9] |
| malic enzyme | [4.5 10.4] | [10.7 18.3] | [14.0 28.0] |
| cytosolic alanine synthesis | [0.0 0.0] | [1.0 1.4] | [0.6 1.2] |
| mitochondrial alanine synthesis | [2.7 3.0] | [0.7 1.1] | [0.5 1.4] |
| glycine synthesis via serine | [1.5 1.8] | [0.2 1.2] | [1.1 1.5] |
| glycine synthesis via threonine | [0.5 0.7] | [0.4 1.5] | [0.0 0.4] |
| NADPH supply by PPP | [107.4 110.8] | [56.2 62.4] | [29.0 31.0] |
| NADPH demand for anabolism | [92.8 100.8] | [61.7 72.8] | [51.4 64.6] |
| Flux Reversibility b | |||
| glucose 6-phosphate isomerase | [19.4 25.5] | [21.2 31.9] | [17.6 30.7] |
| transaldolase | [0.0 0.3] | [0.0 0.3] | [0.0 0.3] |
| transketolase 1 | [2.1 4.0] | [20.7 36.4] | [2.1 2.9] |
| transketolase 2 | [0.0 0.8] | [1.9 4.1] | [0.0 0.2] |
| intercompartmental oxaloacetate transport | [2.1 3.0] | [0.1 0.4] | [0.9 1.9] |
| intercompartmental acetyl CoA transport | [17.4 28.6] | [14.8 32.0] | [17.3 30.1] |
a The 90 % confidence intervals were obtained by a Monte-Carlo approach including 100 independent parameter estimation runs for each scenario with statistically varied experimental data assuming a normal distribution of the experimental error.
b Flux reversibility is defined as ratio of back flux to net flux.