Table 5.
Maximum specific growth rate (μ), yields (Y) of glycerol, biomass and ethanol on glucose and the ratios of glycerol production to biomass formation and acetate consumption to glucose consumption and biomass formation in anaerobic bioreactor batch cultures of S. cerevisiae strains IMX585, IMX888 and IMX860
| Strain | IMX585 | IMX888 | IMX860 |
|---|---|---|---|
| Relevant genotype | GND1 GND2 GPD1 GPD2 | GND1 GND2 gpd2::eutE gpd1Δ | gnd2Δ gnd1::gndA ald6Δ gpd2::eutE gpd1Δ |
| μ (h−1) | 0.28 ± 0.01 | 0.26 ± 0.01 | 0.20 ± 0.01 |
| Y glycerol/glucose (g g−1) | 0.060 ± 0.000 | <0.001 | <0.001 |
| Y biomass/glucose (gx g−1) | 0.076 ± 0.003 | 0.075 ± 0.000 | 0.077 ± 0.000 |
| Y EtOH/glucose (g g−1) | 0.433 ± 0.001 | 0.474 ± 0.001 | 0.489 ± 0.000 |
| Ratio glycerol produced/biomass (mmol g−1x) | 8.50 ± 0.04 | <0.01 | <0.01 |
| Ratio acetate consumed/biomass (mmol g−1x) | 2.44 ± 0.10 | 6.92 ± 0.12 | 8.90 ± 0.04 |
| Ratio acetate consumed/glucose (g g−1) | 0.011 ± 0.00 | 0.032 ± 0.00 | 0.042 ± 0.00 |
Cultures were grown on synthetic medium containing 20 g L−1 glucose and 3 g L−1 acetic acid (pH 5). Yields and ratios were calculated from the exponential growth phase. The ethanol yield on glucose was corrected for evaporation. Values represent average and mean deviation of data from independent duplicate cultures. Carbon recovery in all fermentations was between 95 and 100 %