Table 1.

Plackett-Burman design for screening of significant factors affecting the protease production by Penicillium bilaiae.

Run	Initial pH	Temperature (°C)	MgSO4 (g/L)	NaNO3 (g/L)	KH2PO4 (g/L)	KCl (g/L)	Glucose (g/L)	Response (U/mL)
1	8	40	0.2	3.5	1.5	1.5	8	56.56
2	4	40	0.8	1.5	1.5	1.5	14	35.40
3	8	20	0.8	3.5	0.5	1.5	14	62.07
4	4	40	0.2	3.5	1.5	0.5	14	38.93
5	4	20	0.8	1.5	1.5	1.5	8	53.81
6	4	20	0.2	3.5	0.5	1.5	14	77.83
7	8	20	0.2	1.5	1.5	0.5	14	21.16
8	8	40	0.2	1.5	0.5	1.5	8	83.58
9	8	40	0.8	1.5	0.5	0.5	14	57.62
10	4	40	0.8	3.5	0.5	0.5	8	41.82
11	8	20	0.8	3.5	1.5	0.5	8	186.21
12	4	20	0.2	1.5	0.5	0.5	8	59.60
13	6	30	0.5	2.5	1	1	11	53.88
14	6	30	0.5	2.5	1	1	11	43.73
15	6	30	0.5	2.5	1	1	11	50.22