Table 1 Actual levels for the four variables Box-Behnken design in response surface methodology of the xylanase enzyme extracted from the bacterium Pseudomonas mohnii
Independent variables | symbols | Coded and actual levels | ||
|---|---|---|---|---|
−1(low) | 0 | + 1(high) | ||
Incubation time (h) | A | 12 | 36 | 60 |
pH | B | 6.0 | 7.5 | 9.0 |
Xylan concentration (%) | C | 0.5 | 1 | 1.5 |
Temperature (°C) | D | 35.0 | 42.5 | 50.0 |