Table 1.
Box-Behnken design of three factors and three levels and the experimental results.
| Runing Order | Variables and Their Coded Values | Yields (mg/L) | ||||||
|---|---|---|---|---|---|---|---|---|
| pH | Salinity (‰) | Cluture Time (d) | Ya (WA) | Yb (WB) | ||||
| Code X1 | X1 | Code X2 | X2 | Code X3 | X3 | |||
| 1 | −1 | 4.0 | −1 | 0.0 | 0 | 25 | 5.16 | 1.26 |
| 2 | 1 | 8.0 | 1 | 35.0 | 0 | 25 | 12.28 | 6.21 |
| 3 | −1 | 4.0 | 1 | 35.0 | 0 | 25 | 6.28 | 3.49 |
| 4 | 0 | 6.0 | 1 | 35.0 | 1 | 30 | 10.74 | 5.64 |
| 5 | −1 | 4.0 | 0 | 17.5 | −1 | 20 | 5.66 | 2.80 |
| 6 | 0 | 6.0 | 0 | 17.5 | 0 | 25 | 12.17 | 5.77 |
| 7 | 0 | 6.0 | −1 | 0.0 | 1 | 30 | 5.96 | 2.97 |
| 8 | 1 | 8.0 | 0 | 17.5 | 1 | 30 | 11.92 | 6.53 |
| 9 | 0 | 6.0 | −1 | 0.0 | −1 | 20 | 3.43 | 1.50 |
| 10 | 1 | 8.0 | −1 | 0.0 | 0 | 25 | 7.00 | 3.16 |
| 11 | 0 | 6.0 | 0 | 17.5 | 0 | 25 | 13.15 | 6.55 |
| 12 | 0 | 6.0 | 0 | 17.5 | 0 | 25 | 12.93 | 5.83 |
| 13 | −1 | 4.0 | 0 | 17.5 | 1 | 30 | 9.09 | 4.81 |
| 14 | 1 | 8.0 | 0 | 17.5 | −1 | 20 | 8.14 | 3.62 |
| 15 | 0 | 6.0 | 1 | 35.0 | −1 | 20 | 6.44 | 3.16 |