TABLE 2.
Physiological characterization of a 35-deletion, minimal CCM prototrophic S. cerevisiae strain in aerobic bioreactor batch culturesa
| Growth phase and factor | CEN.PK113-7D (naive reference) | IMX372 (minimal glycolysis) | IMX2538 (minimal CCM) |
|---|---|---|---|
| Glucose phase (μmax, h−1) | 0.37 ± 0.00 | 0.38 ± 0.01* | 0.34 ± 0.00* |
| qs (mmol gDW−1 h−1) | −16.2 ± 0.2 | −15.7 ± 0.7 | −15.4 ± 0.5 |
| qEthanol (mmol gDW−1 h−1) | 23.5 ± 1.5 | 23.1 ± 1.1 | 23.2 ± 2.1 |
| qGlycerol (mmol gDW−1 h−1) | 1.52 ± 0.05 | 1.40 ± 0.02 | 1.11 ± 0.05* |
| qAcetate (mmol gDW−1 h−1) | 0.44 ± 0.03 | 0.82 ± 0.04* | 0.71 ± 0.02* |
| qCO2 (mmol gDW−1 h−1) | 23.4 ± 0.2 | 22.6 ± 0.5 | |
| qO2 (mmol gDW−1 h−1) | −6.8 ± 0.4 | −7.0 ± 0.2 | |
| Ybiomass/glucose (gDW gglucose−1) | 0.13 ± 0.00 | 0.13 ± 0.00 | 0.12 ± 0.00 |
| Yethanol/glucose (mol mol−1) | 1.45 ± 0.09 | 1.48 ± 0.01 | 1.51 ± 0.09 |
| Yglycerol/glucose (mol mol−1) | 0.09 ± 0.00 | 0.09 ± 0.01 | 0.07 ± 0.00* |
| Yacetate/glucose (mol mol−1) | 0.03 ± 0.00 | 0.05 ± 0.00 | 0.05 ± 0.00* |
| Postdiauxic phase | |||
| μmax (h−1) | 0.10 ± 0.00 | 0.12 ± 0.00* | 0.08 ± 0.01* |
| qEthanol (mmol gDW−1 h−1) | −3.10 ± 0.19 | −3.93 ± 0.04* | −3.07 ± 0.31 |
S. cerevisiae strains were grown at pH 5.0 and at 30°C in aerobic bioreactors on synthetic medium with glucose as sole carbon source. Data are presented as averages and standard deviations of 3 biological replicates for S. cerevisiae strains CEN.PK113-7D (naive reference) and IMX2538 (minimal CCM). DW, dry weight. Data for S. cerevisiae IMX372 (minimal glycolysis) were recalculated from the raw data of Solis-Escalante et al. (22) and were obtained with two biological replicates. Statistical significance with respect to CEN.PK113-7D is indicated in boldface with an asterisk (P < 0.05, two-tailed t test, equal variances).