New keratinolytic bacteria in valorization of chicken feather waste

AMB Express

Table 6 Effect evaluation of two regression models from the Box–Behnken design, for the release of soluble proteins and amino acids

Variable	Effect	Standard error	t value	p value
Release of soluble proteins
Intercept	5.8502	0.0353	165.5901	< 0.0001
X₁	0.9987	0.0865	11.5410	< 0.0001
X₂	− 0.3983	0.0865	− 4.6020	0.0037
X₃	0.0172	0.0865	0.1990	0.8488
X₁X₁	0.1400	0.0612	2.2878	0.0621
X₂X₂	− 0.1122	0.0612	− 1.8332	0.1165
X₃X₃	− 0.2128	0.0612	− 3.4768	0.0132
X₁X₂	− 0.0194	0.1224	− 0.1585	0.8792
X₁X₃	− 0.3359	0.1224	− 2.7446	0.0335
X₂X₃	− 0.0680	0.1224	− 0.5552	0.5988
Release of amino acids
Intercept	99.9512	6.8766	14.5349	< 0.0001
X₁	89.8828	16.8442	5.3361	0.0018
X₂	46.1902	16.8442	2.7422	0.0336
X₃	− 18.3162	16.8442	− 1.0874	0.3186
X₁X₁	41.7277	11.9107	3.5034	0.0128
X₂X₂	27.8740	11.9107	2.3403	0.0578
X₃X₃	3.8631	11.9107	0.3243	0.7567
X₁X₂	53.1504	23.8214	2.2312	0.0672
X₁X₃	1.9315	23.8214	0.0811	0.9380
X₂X₃	− 15.3856	23.8214	− 0.6459	0.5423