Table 4.

Box–Behnken experimental design matrix and results

Run	X1a	X2a	X3a	Sucrose	Lactate	Butyrate	n-Caproic acid (g/L)
1	0	− 1	1	12.5	14	18	14.71
2	0	1	1	12.5	26	18	15.78
3	− 1	1	0	5	26	15	15.00
4	1	0	1	20	20	18	15.55
5	− 1	0	− 1	5	20	12	13.89
6	0	0	0	12.5	20	15	16.01
7	1	1	0	20	26	15	15.47
8	0	0	0	12.5	20	15	16.17
9	0	1	− 1	12.5	26	12	15.55
10	0	0	0	12.5	20	15	16.23
11	0	− 1	− 1	12.5	14	12	13.8
12	0	0	0	12.5	20	15	15.89
13	1	0	− 1	20	20	12	15.16
14	− 1	− 1	0	5	14	15	13.39
15	0	0	0	12.5	20	15	15.84
16	− 1	0	1	5	20	18	15.46

^a X1: sucrose, X2: lactate, X3: butyrate