Table 5.
Experimental design and results of the CCD
| Run No. | Coded variables |
Response (U/g dry substrate) |
|||
| x1 (urea) | x2 (Na2CO3) | x3 (MgSO4) | Actual | Predicted | |
| 1 | −1 | 1 | 1 | 13110 | 12842.1 |
| 2 | 0 | 0 | 0 | 14158 | 13958.2 |
| 3 | 0 | 0 | −1.68 | 13110 | 13328.6 |
| 4 | −1 | −1 | 1 | 13022 | 12759.0 |
| 5 | −1 | −1 | −1 | 12948 | 12274.7 |
| 6 | 0 | 0 | 0 | 13922 | 13958.2 |
| 7 | 1 | 1 | −1 | 10900 | 10753.4 |
| 8 | −1 | 1 | −1 | 12936 | 13198.8 |
| 9 | 0 | 0 | 0 | 13684 | 13958.2 |
| 10 | 0 | 0 | 0 | 14084 | 13958.2 |
| 11 | 0 | −1.68 | 0 | 13048 | 13892.4 |
| 12 | 0 | 0 | 0 | 13860 | 13958.2 |
| 13 | 1 | −1 | −1 | 12774 | 12632.4 |
| 14 | 1 | −1 | 1 | 14158 | 13485.7 |
| 15 | 0 | 0 | 0 | 14144 | 13958.2 |
| 16 | −1.68 | 0 | 0 | 10988 | 11351.0 |
| 17 | 1.68 | 0 | 0 | 9690 | 9907.4 |
| 18 | 0 | 1.68 | 0 | 12648 | 12383.9 |
| 19 | 0 | 0 | 1.68 | 13384 | 13745.8 |
| 20 | 1 | 1 | 1 | 10502 | 10765.8 |