Skip to main content

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

From: Optimization and partial purification of beta-galactosidase production by Aspergillus niger isolated from Brazilian soils using soybean residue

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