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Table 2 Metabolites differing in relative abundance in cell pellets and culture supernatants of Clostridium cellulolyticum mdh, ldh and ldh mdh mutants compared to wild-type at stationary growth phase

From: Combined inactivation of the Clostridium cellulolyticum lactate and malate dehydrogenase genes substantially increases ethanol yield from cellulose and switchgrass fermentations

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
  1. 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).
  2. ND = not determined (the concentrations of these metabolites were too low to produce reliable estimates of relative abundance).