Table 1.
Strain | Products (mM) and measurement method | |||||||
---|---|---|---|---|---|---|---|---|
Enzymatic | HPLC | |||||||
l-lac | d-lac | Lac | Ace | Pyr | Mal | Suc | OD600 | |
DSM 4216 wild-type | 15.85 ± 2.22 | 0.73 ± 0.08 | 20.67 ± 1.25 | 9.12 ± 0.49 | 0.21 ± 0.11 | 0.06 ± 0.02 | 0.27 ± 0.10 | 0.785 ± 0.209 |
DSM 4216 ΔldhL | 0.02 ± 0.03 | 4.11 ± 0.86 | 4.95 ± 3.35 | 12.40 ± 3.16 | 1.48 ± 1.14 | 0.35 ± 0.07 | 0.57 ± 0.22 | 0.466 ± 0.057 |
ET 138 wild-type | 20.55 ± 4.09 | 0.87 ± 0.05 | 26.18 ± 7.66 | 8.25 ± 2.59 | 0.78 ± 0.31 | 0.05 ± 0.08 | 0.61 ± 0.16 | 1.036 ± 0.136 |
ET 138 ΔldhL | 0.08 ± 0.09 | 1.08 ± 0.32 | 1.73 ± 0.48 | 14.33 ± 5.54 | 0.76 ± 0.82 | 0.33 ± 0.15 | 0.72 ± 0.22 | 0.581 ± 0.289 |
ET 138 ΔldhL ΔsigF | 0.06 ± 0.05 | 0.95 ± 0.20 | 1.58 ± 0.62 | 10.97 ± 2.13 | 0.70 ± 0.41 | 0.27 ± 0.08 | 0.60 ± 0.16 | 0.672 ± 0.102 |
ET 138 ΔldhL ΔsigF ΔpdhA a | 0.39 ± 0.02 | 11.17 ± 0.47 | 11.50 ± 2.07 | −3.19a ± 1.24 | 8.26 ± 0.82 | 1.12 ± 0.14 | 1.85 ± 0.37 | 0.696 ± 0.119 |
ET 138 ΔldhL ΔsigF + pWUR736 | 18.13 ± 3.82 | 1.11 ± 0.40 | 18.99 ± 5.19 | 7.32 ± 1.33 | 0.24 ± 0.16 | 0.08 ± 0.18 | 0.39 ± 0.17 | 0.831 ± 0.200 |
ET 138 ΔldhL ΔsigF + pNW33n | 0.14 ± 0.04 | 2.57 ± 1.30 | 3.17 ± 1.13 | 10.14 ± 0.91 | 0.94 ± 0.53 | 0.07 ± 0.12 | 0.36 ± 0.08 | 0.535 ± 0.062 |
ET 138 wild-type + pNW33n | 22.12 ± 3.69 | 0.69 ± 0.10 | 21.42 ± 1.51 | 5.63 ± 1.15 | 0.65 ± 0.07 | 0.05 ± 0.12 | 0.34 ± 0.14 | 0.849 ± 0.076 |
Strains were grown in 25 mL TVMY supplemented with 10 g/L glucose in 50 mL Greiner tubes at 55°C for 24 h after transfer from a 10 mL-overnight culture. d- and l-lactate were distinguished via enzymatic assays, for which the lowest detection limit was 0.04 mM. The values shown are the results of three to fourteen independent experiments; numbers in italics are standard deviations.
l -lac l-lactate, d -lac d-lactate, Ace acetate, Pyr pyruvate, Mal malate, Suc succinate.
aThese cultures were supplemented with 3 g/L ammonium acetate.