Table 1 Experimental range and the levels of four independent variables employed in RSM in terms of actual and coded factors
Variables | Levels | ||
|---|---|---|---|
-1 | 0 | +1 | |
Glucose (%, w/v) | 0.75 | 1.00 | 1.25 |
Yeast extract (%, w/v) | 0.30 | 0.50 | 0.70 |
MgSO4 (%, w/v) | 0.0075 | 0.0100 | 0.0125 |
pH | 8.80 | 9.00 | 9.20 |