TABLE 4.
Metabolite profiles of E. faecalis strains cultured under each conditiona
| Strain | Carbon source | O2 | Concn of consumed carbon source (mM) | Metabolite concn (mM) |
Carbon balance (%)b | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| AAL | Acetate | Acetoin | Ethanol | Formate | d-Lactate | l-Lactate | |||||
| W11 | Glucose | + | 50 | <0.1 | 35.1 | 19.1 | <0.1 | 0.2 | 0.1 | 18.5 | 92 |
| − | 50 | <0.1 | <0.1 | 0.3 | 6.2 | 11.7 | 0.1 | 78.8 | 88 | ||
| Δpfl mutant | Glucose | + | 50 | <0.1 | 37.1 | 15.6 | <0.1 | 0.2 | 0.1 | 36.9 | 105 |
| − | 50 | <0.1 | 0.9 | 0.2 | <0.1 | 0.2 | 0.1 | 90.1 | 92 | ||
| W11 | Glycerol | + | 100 | <0.1 | 55.0 | 12.9 | <0.1 | 0.1 | 0.2 | 7.7 | 89 |
| − | 100 | <0.1 | <0.1 | 0.3 | 61.3 | 62.1 | 0.2 | 33.8 | 96 | ||
| Δpfl mutant | Glycerol | + | 100 | <0.1 | 75.2 | 13.0 | 1.1 | <0.1 | 0.1 | 6.6 | 109 |
| − | 36 | <0.1 | 2.6 | 0.2 | 5.4 | 0.2 | 0.2 | 34.3 | 119 | ||
| W11 | DHA | + | 100 | <0.1 | 79.8 | 4.3 | <0.1 | 1.4 | 1.6 | 0.3 | 90 |
| − | 100 | <0.1 | 24.3 | 0.5 | 10.7 | 26.7 | 1.6 | 45.6 | 83 | ||
| Δpfl mutant | DHA | + | 100 | <0.1 | 78.5 | 1.9 | <0.1 | <0.1 | 1.3 | 3.6 | 87 |
| − | 100 | <0.1 | 17.8 | 0.2 | 11.6 | 0.1 | 1.2 | 58.8 | 90 | ||
a
E. faecalis strains were cultured in M-MRS broth containing 50 mM glucose, 100 mM glycerol, or 100 mM DHA for 36 h under aerobic (+) and anaerobic (−) conditions. M-MRS broth contains 36 mM acetate, 0.5 mM ethanol, 0.1 mM formate, 0.3 mM d-lactate, and 11.1 mM l-lactate; metabolite concentrations are presented exclusive of these initial amounts. The results are the means of results from three experiments. The standard errors were all <10%. AAL, acetaldehyde.
b
The concentrations of CO2 (mM) generated by the Pdh and AlsS reactions were calculated as follows. CO2 (Pdh) = (AAL [mM] + acetate [mM] + ethanol [mM]) − formate (mM). CO2 (AlsS) = acetoin (mM).