Identification and statistical optimization of fermentation conditions for a newly isolated extracellular cholesterol oxidase-producing Streptomyces cavourensis strain NEAE-42

Table 9 Analysis of variance (ANOVA) for CCD results used for optimizing cholesterol oxidase production by Streptomyces cavourensis strain NEAE-42

Source	Sum of Squares	df	Mean Square	F-value	P-value Prob > F
Model	364.929	9	40.548	52.771	<0.0001*
X₁ (initial pH)	11.778	1	11.778	15.328	0.0029*
X₂ (cholesterol)	3.386	1	3.386	4.406	0.0622
X₃ (ammonium sulphate)	32.666	1	32.666	42.513	<0.0001*
X₁ X₂	0.032	1	0.032	0.041	0.8432
X₁ X₃	0.462	1	0.462	0.602	0.4558
X₂ X₃	10.254	1	10.254	13.344	0.0044*
X₁ ²	74.961	1	74.961	97.557	<0.0001*
X₂ ²	19.730	1	19.730	25.677	0.0005*
X₃ ²	250.574	1	250.574	326.109	<0.0001*
Residual	7.684	10	0.768
Lack of Fit	7.651	5	1.530	233.149	<0.0001*
Pure Error	0.033	5	0.007
Cor Total	372.613	19

ISSN: 1471-2180