Table 2.

Analysis of variance (ANOVA) of the regression model, involving combined linear (L) and quadratic (Q) effects (L + Q) of input variables and interaction terms (X_a*X_b).

Regression model component	SS	df	MS	F	p
X1: glycerol [g/L] L + Q	47.739	2	23.870	6.758	0.0108
X2: leucine [g/L] L + Q	35.678	2	17.839	5.051	0.0256
X3: phosphate [g/L] L + Q	31.279	2	15.640	4.428	0.0363
X4: urea [g/L] L + Q	52.520	2	26.260	7.435	0.0079
Interactions X1*X2 X1*X3 X1*X4 X2*X3 X2*X4 X3*X4	1.099	1	1.099	0.311	0.5872
	1.0881	1	1.088	0.308	0.5811
	16.485	1	16.485	4.667	0.0517
	13.582	1	13.582	3.846	0.0735
	0.262	1	0.262	0.074	0.7900
	12.325	1	12.325	3.490	0.0864
Residual error	42.382	12	3.532
Total SS	194.465	26

R² = 0.7821.