TABLE 6.
Box–Behnken experimental design for the response surface test and results.
| Test no. | A culture time | B temperature | C pH | D inoculum volume | Y CMCase activity (U/ml) |
| 1 | 1 | 1 | 0 | 0 | 153.937 |
| 2 | 1 | 0 | 0 | −1 | 153.537 |
| 3 | 1 | 0 | 0 | 1 | 156.189 |
| 4 | 1 | 0 | 1 | 0 | 155.426 |
| 5 | 1 | 0 | −1 | 0 | 153.327 |
| 6 | 1 | −1 | 0 | 0 | 157.563 |
| 7 | 0 | 0 | 0 | 0 | 169.755 |
| 8 | 0 | 0 | −1 | −1 | 137.281 |
| 9 | 0 | 0 | 0 | 0 | 170.556 |
| 10 | 0 | 0 | 0 | 0 | 168.324 |
| 11 | 0 | 0 | −1 | 1 | 150.350 |
| 12 | 0 | 1 | 0 | 1 | 152.583 |
| 13 | 0 | 0 | 0 | 0 | 167.713 |
| 14 | 0 | 0 | 1 | −1 | 151.514 |
| 15 | 0 | 1 | 1 | 0 | 158.078 |
| 16 | 0 | −1 | 1 | 0 | 149.530 |
| 17 | 0 | −1 | 0 | 1 | 149.091 |
| 18 | 0 | 0 | 1 | 1 | 150.217 |
| 19 | 0 | 1 | 0 | −1 | 151.800 |
| 20 | 0 | 0 | 0 | 0 | 167.713 |
| 21 | 0 | −1 | −1 | 0 | 145.943 |
| 22 | 0 | −1 | −1 | −1 | 133.655 |
| 23 | 0 | 1 | −1 | 0 | 147.279 |
| 24 | −1 | 0 | −1 | 0 | 143.234 |
| 25 | −1 | −1 | 0 | 0 | 140.219 |
| 26 | −1 | 0 | 1 | 0 | 152.182 |
| 27 | −1 | 0 | 0 | −1 | 143.691 |
| 28 | −1 | 1 | 0 | 0 | 148.881 |
| 29 | −1 | 0 | 0 | 1 | 145.714 |
A, culture time; B, temperature; C, pH; D, inoculum volume. They are four factors in response surface test, as the independent variables. Y indicates CMCase activity that is the response value in response surface test, as the dependent variable.