Table 4.
ANOVA analysis for response surface quadratic model for biosurfactant production in terms of surface tension measurement (mN/m).
| Source | Sum of squares | DF | Mean square | F-Value | p-Value | |
|---|---|---|---|---|---|---|
| Model | 56.54 | 9 | 6.28 | 36.05 | < 0.0001 | Significant |
| A-Yeast extract | 6.53 | 1 | 6.53 | 37.47 | 0.0001 | |
| B-Inoculum size | 7.97 | 1 | 7.97 | 45.77 | < 0.0001 | |
| C-Fermentation time | 20.48 | 1 | 20.48 | 117.52 | < 0.0001 | |
| AB | 3.42 | 1 | 3.42 | 19.62 | 0.0013 | |
| B | 0.30 | 1 | 0.30 | 1.72 | 0.2186 | |
| BC | 4.16 | 1 | 4.16 | 23.88 | 0.0006 | |
| A2 | 2.41 | 1 | 2.41 | 13.82 | 0.0040 | |
| B2 | 0.36 | 1 | 0.36 | 2.06 | 0.1821 | |
| C2 | 1.03 | 1 | 1.03 | 5.89 | 0.0356 | |
| Residual | 1.74 | 10 | 0.17 | |||
| Lack of fit | 1.13 | 5 | 0.23 | 1.82 | 0.2626 | Not significant |
| Pure error | 0.62 | 5 | 0.12 | |||
| Cor total | 58.28 | 19 | ||||
| Std. Dev. | 0.42 | R-squared | 0.9701 | |||
| Mean | 44.53 | Adj R. squared | 0.9432 | |||
| C.V.% | 0.94 | Pred R-squared | 0.8479 | |||
| PRESS | 8.87 | Adeq precision | 21.490 |
Source, A meaningful name for the rows. Sum of Squares, Sum of the squared differences between the overall average and the amount of variation explained by that rows source; DF, Degrees of Freedom: The number of estimated parameters used to compute the source's sum of squares; Mean Square, The sum of squares divided by the degrees of freedom. Also called variance. F Value, Test for comparing the source's mean square to the residual mean square. P-Value, Probability of seeing the observed F-value if the null hypothesis is true (there are no factor effects). Small probability values call for rejection of the null hypothesis. The probability equals the integral under the curve of the F-distribution that lies beyond the observed F-value.