Table 4 Regression analysis for Plackett Burman design variables
Term | Effect | Coefficient | Standard error | T value | P value |
|---|---|---|---|---|---|
Intercept | 8.3376 | 0.1481 | 56.296 | 0.0003 | |
pH | -1.5322 | -0.7661 | 0.1481 | -5.1726 | 0.0354 |
% Inoculum (v/v) | -0.8345 | -0.4173 | 0.1481 | -2.8174 | 0.1063 |
Substrate conc. | 1.6883 | 0.8441 | 0.1481 | 5.6997 | 0.0294 |
Yeast extract | -0.1995 | -0.0997 | 0.1481 | -0.6734 | 0.5701 |
Magnesium sulphate | 0.7329 | 0.3665 | 0.1481 | 2.4744 | 0.1318 |
Ammonium sulphate | 0.6458 | 0.3229 | 0.1481 | 2.1803 | 0.161 |
Sodium di-hydrogen phosphate | -1.984 | -0.992 | 0.1481 | -6.6982 | 0.0216 |
Potassium di-hydrogen phosphate | 0.3705 | 0.1853 | 0.1481 | 1.251 | 0.3374 |
Fermentation time | 1.5751 | 0.7875 | 0.1481 | 5.3174 | 0.0336 |