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.

Frick and Wittmann Microbial Cell Factories 2005 4:30   doi:10.1186/1475-2859-4-30