Sequential Statistical Optimization of Media Components for the Production of Glucoamylase by Thermophilic Fungus Humicola grisea MTCC 352

Table 5

Central composite design matrix for the experimental design and predicted responses for glucoamylase activity.

Trial	Coded variable level				Glucoamylase activity (U/mL)
	𝑍1	𝑍2	𝑍3	𝑍4	Observed	Predicted
1	−1	−1	1	−1	10.73	10.498
2	0	0	0	0	11.56	11.65
3	1	1	1	1	10.2	10.156
4	0	0	0	0	11.72	11.65
5	0	0	2	0	9.42	9.845
6	0	0	0	2	8.41	9.031
7	1	1	−1	−1	8.38	8.186
8	−1	−1	−1	−1	10.56	10.362
9	−1	−1	1	1	8.93	8.883
10	−1	1	1	−1	11.87	11.737
11	−1	1	−1	1	10.22	9.779
12	1	1	1	−1	10.4	10.191
13	−2	0	0	0	11.35	11.703
14	0	0	0	0	11.82	11.65
15	1	−1	−1	1	9.42	9.311
16	1	−1	−1	−1	8.96	8.996
17	2	0	0	0	9.54	9.758
18	0	0	0	0	11.62	11.65
19	0	0	0	−2	9.77	9.72
20	0	0	0	0	11.48	11.65
21	1	−1	1	−1	9.02	9.219
22	−1	1	−1	−1	9.56	9.82
23	0	0	−2	0	8.52	8.666
24	0	−2	0	0	8.69	8.935
25	0	0	0	0	11.71	11.65
26	−1	1	1	1	11.1	10.735
27	0	0	0	0	11.64	11.65
28	1	1	−1	1	9.21	9.113
29	1	−1	1	1	9.16	8.571
30	0	2	0	0	9.65	9.976
31	−1	−1	−1	1	9.83	9.71