Table 2.
Plackett–Burman design matrix with real coded values of six variables to optimize β-glucosidase production by the Neofusicococcum parvum strain F7.
| Run no | Variable level | Enzyme activity (U/ml) | ||||||
|---|---|---|---|---|---|---|---|---|
| Incubation time (days) | pH | Incubation temperature (°C) | Agitation (rpm) | Casein (%) | Glycerol (%) | Observed | Predicted | |
| 1 | + (12) | + (7) | − (20) | + (200) | + (2) | + (0.75) | 1.49 | 1.17 |
| 2 | + (12) | − (5) | − (20) | − (150) | + (2) | + (0.75) | 0.45 | 0.50 |
| 3 | − (8) | − (5) | + (40) | − (150) | + (2) | + (0.75) | 0.02 | 0 |
| 4 | + (12) | + (7) | − (20) | − (150) | − (1.5) | + (0.75) | 0.96 | 1.00 |
| 5 | + (12) | + (7) | + (40) | − (150) | − (1.5) | − (0.25) | 0.02 | 0.07 |
| 6 | − (8) | − (5) | − (20) | + (200) | − (1.5) | + (0.75) | 0.43 | 0.50 |
| 7 | − (8) | − (5) | − (20) | − (150) | − (1.5) | − (0.25) | 0.23 | 0.08 |
| 8 | + (12) | − (5) | + (40) | + (200) | + (2) | − (0.25) | 0.02 | 0 |
| 9 | − (8) | + (7) | − (20) | + (200) | + (2) | − (0.25) | 0.2 | 0.50 |
| 10 | − (8) | + (7) | + (40) | − (150) | + (2) | + (0.75) | 0.02 | 0.15 |
| 11 | − (8) | + (7) | + (40) | + (200) | − (1.5) | − (0.25) | 0.02 | 0 |
| 12 | + (12) | − (5) | + (40) | + (200) | − (1.5) | + (0.75) | 0.03 | 0.23 |
Real values: (), coded values: symbolized as + and –.