Table 3.
Result of Student's t-test for alkaline CMCase activity and the cell growth in the optimization study.
| Term | CMCase activity (U/mL) | Cell growth (g/L) | ||
|---|---|---|---|---|
| t | P | t | P | |
| Constant | 28.927 | 0.000 | 57.032 | 0.000 |
| pH (X 1) | 4.229 | 0.002 | 3.518 | 0.006 |
| Temperature (°C) (X 2) | 8.712 | 0.000 | 4.355 | 0.001 |
| Agitation (rpm) (X 3) | −4.341 | 0.001 | 8.136 | 0.000 |
| (X 1 2 ) | −0.192 | 0.852 | −8.511 | 0.000 |
| (X 2 2) | −7.938 | 0.000 | −13.026 | 0.000 |
| (X 3 2) | −0.728 | 0.483 | −5.272 | 0.000 |
| X 1∗X 2 | −1.848 | 0.094 | −0.207 | 0.840 |
| X 1∗X 3 | 0.387 | 0.707 | 0.259 | 0.801 |
| X 2∗X 3 | −3.332 | 0.008 | 2.482 | 0.032 |
t statistic is the coefficient divided by its standard error, P is probability of incorrectly rejecting the null hypothesis when it is actually true.