Optimization of Fermentation Medium for Extracellular Lipase Production from Aspergillus niger Using Response Surface Methodology

Table 3

ANOVA for lipase activity obtained by A. niger G783.

Source	Degrees of freedom	Sum of squares	Mean square	value	Prob. >
Model	9	704679.1	78297.7	43.89	<0.0001	Significant
	1	75272.0	75272.0	42.20	0.0003
	1	104424.5	104424.5	58.54	0.0001
	1	46818.0	46818.0	26.24	0.0014
	1	43056.2	43056.2	24.14	0.0017
	1	7482.2	7482.2	4.19	0.0798
	1	1056.2	1056.2	0.59	0.4667
	1	148065.8	148065.8	83.01	<0.0001
	1	217012.0	217012.0	121.66	<0.0001
	1	24336.0	24336.0	13.64	0.0077
Residual	7	12485.8	1783.7
Lack of fit	3	1475.0	491.7	0.18	0.9057	Insignificant
Error	4	11010.8	2752.7
Total	16	717164.9

Coefficient of determination () = 0.9828, CV = 2.29%. A model with an value of 43.89 implies that the model is significant, which could occur due to noise. Values of “Prob. > ” less than 0.01 indicate that model terms are significant. In this case, , , , , , , and are significant model terms. The “Predicted ” of 0.9431 is close to the “Adj. -Squared” of 0.9602, which corrects the values for the number of terms and for the sample size in the model. The “adequate precision” value of 22.523 indicates an adequate signal. The lack of fit is insignificant and the model is adequate. This model can be used to navigate the design space.