Table 2.

Design of experiment and response of the central composite experimental design for the production of biosurfactant using B. subtilis SPB1.

Run order	X 1: temperature (°C)	X 2: moisture (%)	X 3: inoculum age (h)	Biosurfactant (mg/g)experimental values	Biosurfactant (mg/g) csalculated values
1	25	50	04	15.22	15.44
2	45	50	04	12.47	13.15
3	25	100	04	15.40	15.18
4	45	100	04	17.40	17.14
5	25	50	24	14.90	15.59
6	45	50	24	14.20	14.88
7	25	100	24	15.85	15.88
8	45	100	24	19.10	19.42
9	18	75	14	16.20	15.93
10	52	75	14	17.40	16.99
11	35	33	14	16.58	15.72
12	35	117	14	19.50	19.32
13	35	75	01	12.50	12.26
14	35	75	31	14.50	14.30
15	35	75	14	14.30	14.35
16	35	75	14	12.80	14.35
17	35	75	14	14.91	14.35
18	35	75	14	13.20	14.35
19	35	75	14	15.80	14.35
20	35	75	14	14.49	14.35
21	28	65	11	14.42	14.45
22	42	69	11	14.74	14.12
23	35	95	11	14.48	15.73
24	35	75	23	15.95	14.59