Table 3.
Analysis of variance for the second-order polynomial model of biomass synthesis by Cunninghamella bainieri 2A1 using repeated batch cultivation at 30°C for 96 h.
| Source | Polynomial coefficients | Sum of squares | DF | Mean square | F value | Prob > F |
|---|---|---|---|---|---|---|
| Model | 58.56 | 9 | 6.51 | 22.88 | <0.0001∗∗ | |
| Intercept | 20.73 | |||||
| X 1 | 0.19 | 0.36 | 1 | 0.36 | 1.27 | 0.2926 |
| X 2 | 1.70 | 28.90 | 1 | 28.90 | 101.61 | <0.0001∗∗ |
| X 3 | 0.040 | 0.016 | 1 | 0.016 | 0.056 | 0.8185 |
| X 1 2 | −0.72 | 1.42 | 1 | 1.42 | 4.98 | 0.0561 |
| X 2 2 | −2.37 | 15.26 | 1 | 15.26 | 53.66 | <0.0001∗∗ |
| X 3 2 | 0.83 | 1.85 | 1 | 1.85 | 6.51 | 0.0341∗ |
| X 1 X 2 | 0.26 | 0.55 | 1 | 0.55 | 1.94 | 0.2014 |
| X 1 X 3 | −0.21 | 0.36 | 1 | 0.36 | 1.27 | 0.2924 |
| X 2 X 3 | 0.51 | 2.10 | 1 | 2.10 | 7.39 | 0.0263∗ |
| Residuals | 2.28 | 8 | 0.28 | |||
| Lack of fit | 2.07 | 5 | 0.41 | 6.0 | 0.0856 | |
| Pure error | 0.21 | 3 | 0.069 |
*Statistically significant at 95% probability level.
**Statistically significant at 99% of probability level.
X 1: glucose concentration (g/L); X 2: ammonium tartrate (g/L); X 3: harvesting time (h). X 1 2, X 2 2, and X 3 2: the quadratic terms; X 1 X 2, X 1 X 3, and X 2 X 3: the interaction terms.
R 2 = 0.9626.