Table 4.

Analysis of variance (ANOVA) for the experimental results of the CCRD

Source	Biomass (g/L)					Specific activity (μmol/min/g)
	SS	df	SM	F-value	P-value*	SS	df	SM	F-value	P-value*
Model	0.22	14	0.015	73.18	< 0.0001	256.26	14	18.30	101.9	< 0.0001
X1	0.081	1	0.081	384.8	< 0.0001	25.74	1	25.74	143.3	< 0.0001
X2	0.0024	1	0.0024	11.30	0.0043	20.99	1	20.99	116.8	< 0.0001
X3	0.024	1	0.024	112.7	< 0.0001	0.11	1	0.11	0.6066	0.4482
X4	0.065	1	0.065	307.5	< 0.0001	120.26	1	120.26	669.5	< 0.0001
X1X2	0.0079	1	0.0079	37.38	< 0.0001	3.11	1	3.11	17.33	0.0008
X1X3	0.0062	1	0.0062	29.43	< 0.0001	8.40	1	8.40	46.80	< 0.0001
X1X4	0.00045	1	0.00045	2.143	0.1638	0.28	1	0.28	1.539	0.2338
X2X3	0.00056	1	0.00056	2.677	0.1226	1.08	1	1.08	6.031	0.0267
X2X4	0.00004	1	0.00004	0.1850	0.6729	0.43	1	0.43	2.383	0.1435
X3X4	0.00066	1	0.00066	3.147	0.0964	27.03	1	27.03	150.5	< 0.0001
X12	0.019	1	0.019	91.35	< 0.0001	22.26	1	22.26	123.9	< 0.0001
X22	0.0068	1	0.0068	32.25	< 0.0001	2.18	1	2.18	12.15	0.0033
X32	0.0088	1	0.0088	41.55	< 0.0001	33.01	1	33.01	183.8	< 0.0001
X42	0.0027	1	0.0027	12.67	0.0029	0.68	1	0.66	3.648	0.0755
Lack of fit	0.0025	10	0.00025	1.89	0.2497	0.88	10	0.088	0.24	0.9722
R2 = 0.9856						R2 = 0.9896

X₁, glucose; X₂, soy peptone; X₃, MnSO₄·H₂O; X₄, initial pH.

*P < 0.05 are significant.

SS: Sum of squares; DF: degrees of freedom; SM: mean squares.