TABLE 1.
List of factors that are used in two-level factorial design: Glucose, carbon-to-nitrogen (C/N) ratio, K2HPO4, MgSO4 × 7 H2O, NaCl, trace element (TE) solution, and vitamin (vit.) solution were selected as factors. Based on the given low and high concentrations, the center point was determined and the experimental plan was designed.
| Factor | Unit | Low concentration | Center point | High concentration |
|---|---|---|---|---|
| Glucose | g L−1 | 50 | 100 | 150 |
| C/N ratio | g g−1 | 50 | 125 | 200 |
| K2HPO4 | g L−1 | 0.5 | 1.25 | 2 |
| MgSO4 × 7 H2O | g L−1 | 0.5 | 1.25 | 2 |
| NaCl | g L−1 | 0.5 | 1.25 | 2 |
| TE-Solution | mL L−1 | 5 | 10 | 15 |
| Vit.-Solution | mL L−1 | 0.5 | 1.25 | 2 |