Optimization of Acid Protease Production by Aspergillus niger I1 on Shrimp Peptone Using Statistical Experimental Design

Table 3

The Box-Behnken design of RSM for optimization of protease production.

Variable	KH2PO4	pH	Temperature	Protease activity
Variable code	X1	X2	X3
Run	Units
	(g/L)		(°C)	(U/mL)
(1)	1	5	27.5	58.11
(2)	1	6.5	25	44.11
(3)	1	6.5	30	82.14
(4)	1	8	27.5	57.09
(5)	1.5	8	25	39.64
(6)	1.5	5	25	37.49
(7)	1.5	5	30	67.17
(8)	1.5	8	30	64.19
(9)	2	5	27.5	56.82
(10)	2	8	27.5	53.17
(11)	2	6.5	25	47.72
(12)	2	6.5	30	53.09
(13)	1.5	6.5	27.5	56.5
(14)	1.5	6.5	27.5	57.72
(15)	1.5	6.5	27.5	52.66
(16)	1.5	6.5	27.5	54.47
(17)	1.5	6.5	27.5	56.39