TABLE 5.

Effects of external supply of pyruvate on the anaerobic fermentation profile of E. coli W3110GFA

StrainConcn of initial carbon source (mM)OD600Concn of substrate or product (mM)aSuccinic acid ratiocFoldd change
GlucosePyruvateGlucosebSuccinic acidLactic acidFormic acidAcetic acidEthanol
W3110501.79 ± 0.115.07 ± 0.452.43 ± 0.0310.62 ± 2.4288.03 ± 0.4240.10 ± 0.205.77 ± 0.060.0171.00
W3110GFA500.73 ± 0.0620.57 ± 3.028.16 ± 0.015.47 ± 0.4927.47 ± 2.9416.48 ± 1.551.88 ± 0.240.1378.29
W3110GFA25501.40 ± 0.0721.46 ± 2.073.28 ± 0.5912.98 ± 0.5141.02 ± 4.2944.98 ± 1.315.50 ± 0.200.0311.82
W3110GFA1001.62 ± 0.02NDe3.11 ± 0.0514.66 ± 1.6766.08 ± 3.5180.43 ± 4.994.82 ± 1.240.0181.06
  • a Anaerobic vial fermentation for 24 h.

  • b Residual glucose concentration.

  • c Calculated as succinic acid/(succinic acid + lactic acid + formic acid + acetic acid + ethanol).

  • d Calculated as succinic acid ratio/succinic acid ratio in the wild-type strain (0.017).

  • e Not detected.