Table 2 Variables and their levels employed in the Plackett–Burman design
Components (g/L) | High levels | Low levels |
|---|---|---|
 + 1 | − 1 | |
Defatted soybean meal | 13.5 | 4.5 |
Glucose | 90 | 30 |
KH2PO4 | 2.5 | 0.5 |
MgSO4.7H2O | 0.3 | 0.1 |
NaMoO4.2H2O | 0.08 | 0.02 |
Trace elements (ml/L) | 1.5 | 0.5 |