Table 1 Coded and real values of factors in the central composite rotatable experimental design
Factor | Level of factor | ||||
|---|---|---|---|---|---|
− 2 | − 1 | 0 | 1 | 2 | |
Sodium acetate (A, g/L) | 0.05 | 1.70 | 3.35 | 5.00 | 6.65 |
Meat extract (B, g/L) | 0.25 | 3.50 | 6.75 | 10.00 | 13.25 |
Dipotassium phosphate (C, g/L) | 0.05 | 0.70 | 1.35 | 2.00 | 2.65 |
Yeast extract (D, g/L) | 0.05 | 1.70 | 3.35 | 5.00 | 6.65 |