Optimizing Culture Conditions by Statistical Approach to Enhance Production of Pectinase from Bacillus sp. Y1

Table 4

Experimental design and pectinase activities (U/mL) of the central composite design.

Run no.	Experimental factors and code levels			PGL		PG
	Carbon source	(NH4)2SO4	Initial pH	Experiment	Predicted	Experiment	Predicted
	(%, v/w)	(%, v/w)
1	–1 (9.00)	+1 (0.45)	–1 (7.50)	22.1 ± 0.6	23.8	31.9 ± 0.8	32.3
2	–1.68 (8.32)	0 (0.30)	0 (8.50)	23.2 ± 0.9	23.3	31.7 ± 1.0	32.0
3	0 (10.00)	0 (0.30)	0 (8.50)	26.9 ± 1.1	26.9	33.8 ± 1.4	33.7
4	+1 (11.00)	+1 (0.45)	+1 (9.50)	21.8 ± 0.7	23.4	34.7 ± 0.9	34.5
5	0 (10.00)	0 (0.30)	0 (8.50)	26.9 ± 1.1	26.9	33.8 ± 1.4	33.7
6	0 (10.00)	0 (0.30)	0 (8.50)	26.9 ± 1.1	26.9	33.8 ± 1.4	33.7
7	0 (10.00)	0 (0.30)	0 (8.50)	26.9 ± 1.1	26.9	33.8 ± 1.4	33.7
8	0 (10.00)	–1.68 (0.05)	0 (8.50)	6.5 ± 0.3	9.0	17.7 ± 1.0	18.7
9	0 (10.00)	0 (0.30)	–1.68 (6.82)	23.2 ± 1.0	23.8	31.6 ± 0.9	31.5
10	+1.68 (11.68)	0 (0.30)	0 (8.50)	24.6 ± 0.5	25.3	35.3 ± 0.4	35.9
11	0 (10.00)	0 (0.30)	0 (8.50)	26.9 ± 1.1	26.9	33.8 ± 1.4	33.7
12	0 (10.00)	+1.68 (0.55)	0 (8.50)	26.0 ± 0.5	24.2	32.1 ± 1.1	32.0
13	+1 (11.00)	+1 (0.45)	–1 (7.50)	24.8 ± 0.8	24.1	34.7 ± 0.7	34.5
14	+1 (11.00)	–1 (0.15)	+1 (9.50)	13.3 ± 0.6	11.0	22.4 ± 1.1	21.3
15	+1 (11.00)	–1 (0.15)	–1 (7.50)	23.2 ± 0.9	22.9	28.3 ± 0.6	28.2
16	–1 (9.00)	+1 (0.45)	+1 (9.50)	26.0 ± 0.9	25.8	28.9 ± 0.8	28.4
17	0 (10.00)	0 (0.30)	0 (8.50)	26.9 ± 1.1	26.9	33.8 ± 1.4	33.7
18	0 (10.00)	0 (0.30)	+1.68 (10.18)	15.2 ± 0.6	15.4	21.4 ± 1.2	22.5
19	–1 (9.00)	–1 (0.15)	+1 (9.50)	8.7 ± 0.3	8.9	19.4 ± 0.3	18.9
20	–1 (9.00)	–1 (0.15)	–1 (7.50)	20.3 ± 0.4	18.1	30.1 ± 0.6	29.7

All figures in parenthesis are the actual value of factors in the experiments.