Response Surface Optimization of Bioethanol Production from Sugarcane Molasses by Pichia veronae Strain HSC-22

Table 2

Experimental design matrix with experimental and predicted bioethanol yield.

Run number	Initial pH	Molasses; concentration	Incubation; temperature	Mixing; rate	Incubation; period	Bioethanol; concentration; g/L	Bioethanol yield
							%
							Actual	Predicted
1	0	−1	0	0	0	18.2	41.4	39.1
2	−1	−1	−1	−1	+1	4.01	9.13	11.2
3	1	−1	−1	−1	+1	6.29	14.3	13.2
4	0	0	0	−1	0	19.3	33.0	34.1
5	0	0	0	0	+1	18.4	31.4	29.7
6	−1	0	0	0	0	15.3	26.1	22.6
7	0	0	−1	0	0	20.3	34.7	34.8
8	+1	−1	−1	+1	−1	4.61	10.5	13.9
9	+1	+1	+1	+1	+1	22.3	30.5	26.5
10	−1	+1	+1	−1	+1	19.5	26.7	23.9
11	−1	−1	+1	−1	−1	3.96	9.02	10.9
12	−1	−1	+1	−1	+1	6.48	14.8	16.5
13	+1	−1	+1	−1	−1	4.64	10.6	10.3
14	0	+1	0	0	0	23.5	32.1	38.9
15	+1	−1	+1	+1	+1	8.90	20.3	24.2
16	0	0	0	0	0	20.6	35.2	35.4
17	0	0	0	+1	0	22.1	37.7	37.7
18	−1	−1	−1	+1	−1	4.31	9.82	10.2
19	0	0	0	0	0	21.3	36.4	35.4
20	−1	+1	+1	+1	−1	8.80	12.0	13.5
21	0	0	+1	0	0	21.5	36.7	37.7
22	+1	+1	+1	+1	−1	9.44	12.9	13.5
23	+1	−1	+1	−1	+1	7.96	18.1	15.9
24	0	0	0	0	0	21.4	36.6	35.4
25	+1	0	0	0	0	11.1	19.0	23.6
26	0	0	0	0	0	20.9	35.6	35.4
27	0	0	0	0	0	21.3	36.4	35.4
28	+1	+1	−1	+1	−1	11.9	16.2	13.0
29	−1	+1	+1	+1	+1	19.4	26.5	26.6
30	0	0	0	0	0	21.3	36.4	35.4
31	−1	+1	−1	−1	−1	8.45	11.6	11.4
32	+1	+1	+1	−1	+1	14.7	20.1	22.2
33	+1	+1	−1	−1	−1	10.8	14.8	12.5
34	−1	−1	−1	−1	−1	3.39	7.72	7.13
35	+1	+1	−1	+1	+1	17.1	23.4	24.5
36	0	0	0	0	0	20.9	35.7	35.4
37	+1	−1	−1	−1	−1	3.60	8.20	9.26
38	+1	−1	−1	+1	+1	10.7	24.4	22.9
39	0	0	0	0	−1	10.8	18.4	21.1
40	0	0	0	0	0	20.6	35.3	35.4
41	+1	+1	+1	−1	−1	10.6	14.5	14.2
42	−1	−1	+1	+1	+1	9.54	21.7	23.4
43	+1	−1	+1	+1	−1	7.07	16.1	13.7
44	+1	+1	−1	−1	+1	13.6	18.5	19.0
45	0	−1	+1	+1	−1	6.26	14.3	12.7
46	0	+1	−1	−1	+1	12.9	17.7	17.9
47	0	+1	−1	+1	−1	7.31	9.99	10.3
48	0	+1	−1	+1	+1	15.7	21.5	21.9
49	0	+1	+1	−1	−1	12.2	16.7	15.8
50	0	−1	−1	+1	+1	8.74	19.9	19.3