Table 2.

The design and results of the central composite rotatable design (CCRD) experiments

Run	Factor				Biomass (g/L)		Specific activity (μmol/min/g)
	X1	X2	X3	X4	Observed	Predicted	Observed	Predicted
1	-1	-1	-1	-1	1.02	1.03	36.35	36.42
2	1	-1	-1	-1	1.13	1.13	33.61	33.52
3	-1	1	-1	-1	0.96	0.95	40.03	40.02
4	1	1	-1	-1	1.15	1.14	35.43	35.36
5	-1	-1	1	-1	1.01	1.00	32.87	33.03
6	1	-1	1	-1	1.03	1.03	33.12	33.02
7	-1	1	1	-1	0.97	0.96	35.56	35.59
8	1	1	1	-1	1.07	1.07	34.01	33.82
9	-1	-1	-1	1	0.92	0.93	38.35	38.36
10	1	-1	-1	1	1.04	1.05	36.15	35.99
11	-1	1	-1	1	0.85	0.85	41.35	41.31
12	1	1	-1	1	1.05	1.06	37.50	37.17
13	-1	-1	1	1	0.88	0.88	40.23	40.17
14	1	-1	1	1	0.91	0.92	40.86	40.69
15	-1	1	1	1	0.82	0.82	42.16	42.07
16	1	1	1	1	0.97	0.96	41.04	40.83
17a	-2	0	0	0	0.83	0.83	38.43	38.24
18a	2	0	0	0	1.07	1.07	33.59	34.10
19a	0	-2	0	0	1.03	1.01	36.76	36.77
20a	0	2	0	0	0.96	0.97	40.21	40.51
21a	0	0	-2	0	1.06	1.05	35.09	35.25
22a	0	0	2	0	0.91	0.92	35.36	35.52
23a	0	0	0	-2	1.11	1.12	34.73	34.67
24a	0	0	0	2	0.93	0.91	43.26	43.63
25b	0	0	0	0	1.04	1.06	40.32	39.77
26b	0	0	0	0	1.05	1.06	39.07	39.77
27b	0	0	0	0	1.06	1.06	39.44	39.77
28b	0	0	0	0	1.07	1.06	40.23	39.77
29b	0	0	0	0	1.05	1.06	39.19	39.77
30b	0	0	0	0	1.07	1.06	40.37	39.77

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

^a Axial point.

^b Central point.