Table 4 Independent variables and their levels for Box–Behnken design
Factor | Name | Low actual | High actual | Low coded | High coded |
|---|---|---|---|---|---|
A | Colloidal chitin | 0.1 | 1 | − 1 | 1 |
B | Xylose | 0.2 | 2 | − 1 | 1 |
C | Peptone | 0.2 | 1 | − 1 | 1 |
D | Dihydrogen potassium phosphate | 0.1 | 0.4 | − 1 | 1 |