Table 5.
Physiological parameters of glucose-grown aerobic bioreactor-batch and chemostat cultures (30°C) of wild-type O. parapolymorpha and strains carrying null mutations in genes involved in mitochondrial oxidation of NADH. Batch culture data were derived from analyses on samples taken during the exponential growth phase. Data on aerobic chemostat cultures were derived from a separate study (Juergens et al. 2021). Chemostat cultures (D = 0.1 h–1) and batch cultures were grown on 20 g l–1 glucose and 7.5 g l–1 glucose, respectively. Data are represented as mean ± standard deviation of data obtained from replicate cultures. Negative and positive biomass-specific conversion rates (q) represent consumption and production rates, respectively, with subscript x denoting biomass dry weight. B.D.: below detection limit (concentration < 0.1 mM) and N.D.: not determined.
| O. parapolymorpha strain | CBS11895 | IMX2167 | CBS11895 | IMX2167 |
|---|---|---|---|---|
| Relevant genotype | Wld type | ndh1-3Δ gut2Δ | Wild type | ndh1-3Δ gut2Δ |
| Replicates | 2 | 2 | 2 | 2 |
| Cultivation mode | Batch | Batch | Chemostat | Chemostat |
| Biomass-specific conversion rates | ||||
| Specific growth rate (h–1) | 0.36 ± 0.01 | 0.26 ± 0.00 | 0.10 ± 0.00 | 0.10 ± 0.00 |
| qglucose (mmol gx h–1) | −3.90 ± 0.21 | −2.73 ± 0.08 | −1.08 ± 0.04 | −1.04 ± 0.00 |
| qethanol (mmol gx h–1) | B.D. | 0.22 ± 0.11 | B.D. | B.D. |
| qglycerol (mmol gx h–1) | B.D. | 0.34 ± 0.01 | B.D. | B.D. |
| qO2 (mmol gx h–1) | N.D. | −3.65 ± 0.07 | −2.69 ± 0.07 | −2.14 ± 0.00 |
| qCO2 (mmol gx h–1) | N.D. | 4.34 ± 0.02 | 2.82 ± 0.04 | 2.25 ± 0.00 |
| Stoichiometries | ||||
| RQ (-qCO2/qO2) | N.D. | 1.19 ± 0.03 | 1.05 ± 0.01 | 1.05 ± 0.00 |
| YX/glucose (gx g–1) | 0.52 ± 0.01 | 0.51 ± 0.01 | 0.51 ± 0.00 | 0.52 ± 0.00 |
| YX/O2 (gx mmol–1) | N.D. | 0.07 ± 0.00 | 0.04 ± 0.00 | 0.05 ± 0.00 |
| Recoveries (out/in) | ||||
| Carbon (%) | N.D. | 97.8 ± 1.4 | 99.3 ± 1.7 | 98.7 ± 0.4 |