Box–Behnken experimental design for optimization of parameters for biosurfactant production.

Run	Corn steep liquor (A)	MgSO4 (B)	Peptone (C)	Observed biosurfactant yield (g L−1)	Predicted biosurfactant yield (g L−1)
1	0	1	1	2.51	2.44
2	1	0	1	3.09	3.08
3	−1	−1	0	3.32	3.24
4	0	−1	−1	2.70	2.77
5	1	1	0	3.27	3.35
6	0	0	0	3.88	3.92
7	−1	1	0	2.31	2.28
8	0	−1	1	3.36	3.33
9	0	0	0	3.91	3.92
10	1	0	−1	3.43	3.33
11	0	0	0	3.97	3.92
12	1	−1	0	3.66	3.69
13	0	1	−1	2.33	2.35
14	−1	0	−1	1.98	1.99
15	−1	0	1	2.79	2.89