Table 1 Plackett–Burman design at two levels applied to select the factors that significantly affect uricase production by Aspergillus welwitschiae.
Run no. | Coded levels of the selected independent variables | Uricase activity (U/mL) | Residuals | |||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Incubation time | Temperature | pH | Inoculum size | Inoculums age | Medium volume | Sucrose | Peptone | Uric acid | Yeast extract | NaNO3 | K2HPO4 | MgSO4.7H2O | NaCl | FeSO4. 7H2O | D 1 | D 2 | D 3 | D4 | Actual | Predicted | ||
1 | 1 | 1 | −1 | −1 | 1 | 1 | −1 | 1 | 1 | −1 | −1 | −1 | −1 | 1 | −1 | 1 | −1 | 1 | 1 | 48.2 | 49.22 | −1.02 |
2 | −1 | 1 | 1 | −1 | −1 | −1 | −1 | 1 | −1 | 1 | −1 | 1 | 1 | 1 | 1 | −1 | −1 | 1 | 1 | 20.92 | 22.17 | −1.25 |
3 | −1 | −1 | −1 | −1 | 1 | −1 | 1 | −1 | 1 | 1 | 1 | 1 | −1 | −1 | 1 | 1 | −1 | 1 | 1 | 46.38 | 47.40 | −1.02 |
4 | 1 | 1 | 1 | 1 | −1 | −1 | 1 | 1 | −1 | 1 | 1 | −1 | −1 | −1 | −1 | 1 | −1 | 1 | −1 | 58.21 | 58.95 | −0.74 |
5 | −1 | −1 | 1 | −1 | 1 | −1 | 1 | 1 | 1 | 1 | −1 | −1 | 1 | 1 | −1 | 1 | 1 | −1 | −1 | 31.83 | 30.58 | 1.25 |
6 | −1 | 1 | −1 | 1 | −1 | 1 | 1 | 1 | 1 | −1 | −1 | 1 | 1 | −1 | 1 | 1 | −1 | −1 | −1 | 30.01 | 30.88 | −0.87 |
7 | −1 | 1 | 1 | −1 | 1 | 1 | −1 | −1 | −1 | −1 | 1 | −1 | 1 | −1 | 1 | 1 | 1 | 1 | −1 | 30.92 | 29.54 | 1.38 |
8 | 1 | 1 | 1 | −1 | −1 | 1 | 1 | −1 | 1 | 1 | −1 | −1 | −1 | −1 | 1 | −1 | 1 | −1 | 1 | 58.21 | 57.47 | 0.74 |
9 | 1 | 1 | −1 | 1 | 1 | −1 | −1 | −1 | −1 | 1 | −1 | 1 | −1 | 1 | 1 | 1 | 1 | −1 | −1 | 57.29 | 56.04 | 1.25 |
10 | 1 | −1 | 1 | −1 | 1 | 1 | 1 | 1 | −1 | −1 | 1 | 1 | −1 | 1 | 1 | −1 | −1 | −1 | −1 | 47.29 | 48.40 | −1.11 |
11 | −1 | 1 | 1 | 1 | 1 | −1 | −1 | 1 | 1 | −1 | 1 | 1 | −1 | −1 | −1 | −1 | 1 | −1 | 1 | 42.74 | 42.00 | 0.74 |
12 | 1 | −1 | 1 | 1 | 1 | 1 | −1 | −1 | 1 | 1 | −1 | 1 | 1 | −1 | −1 | −1 | −1 | 1 | −1 | 47.29 | 48.27 | −0.98 |
13 | −1 | 1 | −1 | 1 | 1 | 1 | 1 | −1 | −1 | 1 | 1 | −1 | 1 | 1 | −1 | −1 | −1 | −1 | 1 | 40.01 | 41.39 | −1.38 |
14 | 1 | −1 | −1 | 1 | 1 | −1 | 1 | 1 | −1 | −1 | −1 | −1 | 1 | −1 | 1 | −1 | 1 | 1 | 1 | 43.83 | 42.96 | 0.87 |
15 | 1 | 1 | −1 | −1 | −1 | −1 | 1 | −1 | 1 | −1 | 1 | 1 | 1 | 1 | −1 | −1 | 1 | 1 | −1 | 44.20 | 43.05 | 1.15 |
16 | 1 | −1 | 1 | 1 | −1 | −1 | −1 | −1 | 1 | −1 | 1 | −1 | 1 | 1 | 1 | 1 | −1 | −1 | 1 | 43.65 | 44.80 | −1.15 |
17 | −1 | −1 | −1 | 1 | −1 | 1 | −1 | 1 | 1 | 1 | 1 | −1 | −1 | 1 | 1 | −1 | 1 | 1 | −1 | 46.93 | 45.78 | 1.15 |
18 | −1 | −1 | −1 | −1 | −1 | −1 | −1 | −1 | −1 | −1 | −1 | −1 | −1 | −1 | −1 | −1 | −1 | −1 | −1 | 29.1 | 30.21 | −1.11 |
19 | 1 | −1 | −1 | −1 | −1 | 1 | −1 | 1 | −1 | 1 | 1 | 1 | 1 | −1 | −1 | 1 | 1 | −1 | 1 | 40.92 | 39.94 | 0.98 |
20 | −1 | −1 | 1 | 1 | −1 | 1 | 1 | −1 | −1 | −1 | −1 | 1 | −1 | 1 | −1 | 1 | 1 | 1 | 1 | 35.47 | 34.36 | 1.11 |
Level | Days | °C | pH | mL/50 mL medium | Hour | mL | g/L | g/L | g/L | g/L | g/L | g/L | g/L | g/L | g/L | |||||||
−1 | 4 | 25 | 6 | 1 | 48 | 25 | 20 | 0.5 | 3 | 0.5 | 0.5 | 1 | 0.2 | 0.2 | 0.01 | |||||||
1 | 7 | 35 | 8 | 4 | 72 | 50 | 30 | 2 | 5 | 2 | 2 | 2 | 0.8 | 0.8 | 0.03 | |||||||
