Table 1 Variables values of a 23 factorial design with centered face and three repetitions at the central point used to evaluate the influence of (X1) speed agitation, (X2) temperature and (X3) pH on β-galactosidase production
Variables | Symbol code | Levels | ||
|---|---|---|---|---|
− 1 | 0 | 1 | ||
Speed agitation (rpm) | X 1 | 100 | 120 | 140 |
Temperature (oC) | X 2 | 22 | 28 | 34 |
pH | X 3 | 5 | 7 | 9 |