Table 2.
Compound | Cell pellets: abundance ratio to wild-type | Culture supernatants: abundance ratio to wild-type | ||||
---|---|---|---|---|---|---|
mdh | ldh | mdh-ldh | mdh | ldh | mdh-ldh | |
Malic acid | 0.32 | 1.48 | 0.28 | 0.84 | 1.44 | 0.57 |
2-Hydroxyglutaric acid | 0.28 | 1.42 | 12.43 | 0.35 | 1.72 | 4.94 |
Valine | 0.27 | 1.01 | 0.37 | 0.35 | 1.17 | 0.68 |
Glucose-1-P | 0.90 | 1.20 | 0.56 | 0.89 | 1.36 | 0.57 |
Fructose-6-P | 0.70 | 0.99 | 0.79 | 0.99 | 2.89 | 1.39 |
Glucose-6-P | 0.39 | 1.11 | 1.12 | 1.41 | 9.21 | 4.69 |
Succinic acid | 0.51 | 0.56 | 1.12 | 0.58 | 0.92 | 0.62 |
Fumaric acid | 0.31 | 0.70 | 0.40 | 0.48 | 0.79 | 0.36 |
p-Hydroxybenzoic acid | 0.53 | 0.65 | 1.24 | 0.46 | 0.98 | 1.77 |
10.13 191 246 376 348 | 0.22 | 0.88 | 0.25 | 0.35 | 1.13 | 0.90 |
Citric acid | 0.12 | 0.96 | 6.03 | ND | ND | ND |
11.05 191 276 | 0.44 | 1.53 | 0.18 | ND | ND | ND |
4-Methyl-2-hydroxypentanoic acid | ND | ND | ND | 0.17 | 0.91 | 2.63 |
Pyruvic acid | 0.56 | 0.45 | 0.88 | 0.18 | 2.25 | 0.95 |
Galactose | ND | ND | ND | 3.41 | 2.67 | 2.32 |
2,3-Butanediol | ND | ND | ND | 0.29 | 1.76 | 1.92 |
9.97 331 359 226 | ND | ND | ND | 0.11 | 1.62 | 2.12 |
11.07 191 348 320 246 | ND | ND | ND | 0.73 | 1.46 | 0.44 |
Metabolites were analyzed by gas chromatography-mass spectrometry (GC-MS) as trimethylsilyl (TMS) derivatives, using a sorbitol internal standard [42]. Peaks that could not be assigned to a standard metabolite are identified by their chromatographic retention times (in min) and their characteristic ion peaks (m/z in italic text).
ND = not determined (the concentrations of these metabolites were too low to produce reliable estimates of relative abundance).