Optimization of cultivation medium and cyclic fed-batch fermentation strategy for enhanced polyhydroxyalkanoate production by Bacillus thuringiensis using a glucose-rich hydrolyzate

Bioresources and Bioprocessing

Table 3 ANOVA for response surface quadratic model for biomass production by B. thuringiensis

Source	Sum of squares	Degrees of freedom	Mean square	F-value	p-value
Model	1.94	14	0.1384	16.13	< 0.0001**
A-yeast extract	0.0580	1	0.0580	6.75	0.0266*
B-hydrolyzate	0.6956	1	0.6956	81.04	< 0.0001**
C-pH	0.0001	1	0.0001	0.0162	0.9012
D-time	0.4058	1	0.4058	47.27	< 0.0001**
AB	0.0260	1	0.0260	3.03	0.1122
AC	0.0113	1	0.0113	1.31	0.2789
AD	0.0024	1	0.0024	0.2837	0.6059
BC	0.1443	1	0.1443	16.81	0.0021*
BD	0.0118	1	0.0118	1.38	0.2677
CD	3.306 × 10^–7	1	3.306 × 10^–7	0.0000	0.9952
A²	0.0230	1	0.0230	2.68	0.1329
B²	0.4661	1	0.4661	54.30	< 0.0001**
C²	0.2391	1	0.2391	27.85	0.0004**
D²	0.1417	1	0.1417	16.50	0.0023*
Residual	0.0858	10	0.0086
R²	0.9576
Adjusted R²	0.8982