Table 1 Experimental range and levels of independent factors in the Plackett–Burman design
Factor | Unit | Symbol | Levels | ||
|---|---|---|---|---|---|
Low − 1 | Center 0 | High + 1 | |||
Glucose | g L−1 | C | 0 | 1 | 5 |
Yeast extract | g L−1 | N | 0 | 4 | 8 |
NaCl | g L−1 | Salt | 0.1 | 0 | 2 |
Sodium nitrate | g L−1 | NO3 | 0.1 | 0 | 2 |
Ferrous sulfate FeSO4·7H2O | g L−1 | Fe | 0 | 0.01 | 0.5 |
Magnesium sulfate MgSO4·7H2O | g L−1 | Mg | 0 | 0.5 | 1 |
Initial pH | pH | pH | 5 | 7 | 8 |
Temperature | °C | Temp | 25 | 30 | 37 |
Dye concentration | mg L−1 | Conc | 25 | 50 | 250 |
EDTA | mM | EDTA | 0.1 | 0 | 2 |
Sodium acetate | g L−1 | Acetate | 0.1 | 0 | 1 |