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Table 2 Comparison of different estimations of the non-measured fluxes

From: A procedure for the estimation over time of metabolic fluxes in scenarios where measurements are uncertain and/or insufficient

Ref (v1, v6, v7, v19, v20, v22)

G (no v22)

F (no v20)

E (no v19)

B (no v6)

A (no v1)

C (no v7)

I (no v20v22)

H (no v19v22)

Reactions d

MIa [b]

MI [a]

[%c]

MI [b]

[%]

MI [b]

[%]

MI [b]

[%]

MI [b]

[%]

MI [b]

[%]

MI [b]

[%]

MI [b]

[%]

1: G→G6P

0.267e

0.267

-

0.267

-

0.267

-

0.267

-

x

-

0.267

-

0.267

-

0.267

-

2: G6P→G3P+DAP

0.367

0.387

5%

0.628

71%

0.541

47%

0.398

8%

x

-

0.627

71%

0.628

71%

0.572

56%

3: G6P→R5P+CO2

0.131

0.199

53%

0.526

303%

0.340

160%

0.131

0%

0.131

0%

0.401

207%

0.526

303%

0.383

193%

4: DAP→G3P

0.367

0.387

5%

0.628

71%

0.541

47%

0.398

8%

x

-

0.627

71%

0.628

71%

0.572

56%

5: G3P→Pyr

0.735

0.774

5%

1.256

71%

1.082

47%

0.795

8%

x

-

1.253

71%

1.256

71%

1.144

56%

6: Pyr→L

0.475

0.475

-

0.475

-

0.475

-

x

-

0.475

-

0.475

-

0.475

-

0.475

-

7: Pyr+Glu→A+aKG

0.100

0.100

-

0.100

-

0.100

-

0.100

-

0.100

-

1.488

inf

0.100

-

0.100

-

8: Pyr→ACA+CO2

1.031

1.031

0%

1.562

51%

1.901

84%

x

-

x

-

0.957

-7%

1.562

51%

1.906

85%

9: Oxa+ACA→Cit

1.031

1.031

0%

1.562

51%

1.901

84%

x

-

x

-

0.957

-7%

1.562

51%

1.906

85%

10: Cit→aKG+CO2

1.031

1.031

0%

1.562

51%

1.901

84%

x

-

x

-

0.957

-7%

1.562

51%

1.906

85%

11: aKG→Mal+CO2

1.156

1.156

0%

1.604

39%

2.532

119%

x

-

x

-

1.443

25%

1.604

39%

2.530

119%

12: Mal→Oxa

0.994

0.994

0%

1.398

41%

1.769

78%

x

-

x

-

1.093

10%

1.398

41%

1.769

78%

13: Mal→Pyr+CO2

0.209

0.240

15%

0.352

68%

0.920

341%

0.209

0%

0.209

0%

0.903

332%

0.352

68%

0.918

340%

14: Oxa+Glu→Asp+aKG

0.131

0.199

53%

0.526

303%

0.340

160%

0.131

0%

0.131

0%

0.401

207%

0.526

303%

0.383

193%

15: Glu→aKG+NH4

0.150

0.182

21%

0.298

98%

0.870

479%

0.150

0%

0.150

0%

0.586

289%

0.298

98%

0.870

479%

16: Q→Glu+NH4

0.117

0.145

23%

0.325

177%

0.553

372%

0.117

0%

0.117

0%

0.569

386%

0.325

177%

0.548

367%

17: R5P+Asp+Q→Pu

0.104

0.277

165%

0.293

181%

0.200

91%

0.104

0%

0.104

0%

0.225

116%

0.526

404%

0.383

267%

18: R5P+Asp+2Q→Py

0.078

0.132

69%

0.283

262%

0.177

126%

0.078

0%

0.078

0%

0.209

168%

0.263

237%

0.163

108%

19:→NH4

0.141

0.141

-

0.141

-

1.419

904%

0.141

-

0.141

-

0.141

-

0.141

-

1.412

899%

20:→Q

0.132

0.132

-

1.127

752%

0.132

-

0.132

-

0.132

-

0.132

-

1.107

737%

0.132

-

21:→CO2

3.338

3.338

0%

4.770

43%

6.966

109%

x

-

x

-

3.843

15%

4.770

43%

6.966

109%

22: Pu-Py (constraint)

0.100

0.354

254%

0.100

-

0.100

-

0.100

-

0.100

-

0.100

-

0.526

426%

0.383

283%

Mean

0.554

0.587

39%

0.899

155%

1.138

196%

0.217

2%

0.156

0%

0.802

122%

0.927

180%

1.168

214%

Measured fluxes [number]

6

5

5

5

5

5

5

4

4

Estimated fluxes [number]

16/16

17/17

17/17

17/17

7/17

10/17

17/17

18/18

18/18

<25% (·Ref)

  

12

 

0

 

0

 

10

 

7

 

5

 

0

 

0

25–100% (<2·Ref)

  

3

 

11

 

8

 

0

 

0

 

4

 

11

 

7

100–300% (2–4·Ref)

  

2

 

3

 

5

 

0

 

0

 

5

 

2

 

7

>300% (>4·Ref)

  

0

 

3

 

4

 

0

 

0

 

3

 

5

 

4

  1. Column Ref: FSA is applied by using the six available measurements (Determined case). Columns F, G, E B, A and C: FSA is applied by using a different set of 5 measurements in each case (underdetermined, 1 degree of freedom). Columns I and H: FSA is applied by using two different sets of 4 measurements (underdetermined, 2 degrees of freedom). In all cases the band of uncertainty described in the text has been used. a Mean interval size along time evolution; b in [mM/(d * 10^9 cells)]; c Intervals enlargement w.r.t. case Ref. (in percentage); d The nomenclature is given in the additional file 1; e Measured values are in bold.