Ethanol Production from Oil Palm Trunk: A Combined Strategy Using an Effective Pretreatment and Simultaneous Saccharification and Cofermentation

Table 1

Optimization experiment design and ethanol production performance of S. cerevisiae and P. stipitis coculture by simultaneous saccharification and cofermentation (SSCF).

No.	Temperature (°C)	Fermentation time (days)	Cell ratio	Variable			Ethanol (% v/v) (Y1)	Fermentation efficiency (%) (Y2)
				X1	X2	X3
1	35	7	0.75	+1	+1	+1	1.34	30.03
2	35	7	0.25	+1	+1	-1	0.87	18.61
3	35	3	0.75	+1	−1	+1	1.50	62.63
4	35	3	0.25	+1	−1	−1	1.45	49.21
5	25	7	0.75	−1	+1	+1	1.34	40.16
6	25	7	0.25	−1	+1	−1	0.64	19.18
7	25	3	0.75	−1	−1	+1	0.67	24.17
8	25	3	0.25	−1	−1	−1	0,58	20.99
9	38	5	0.50	+1.682	0	0	0.88	69.46
10	22	5	0.50	−1.682	0	0	1.34	46.50
11	30	8 days, 10 h	0.50	0	+1.682	0	0.78	22.41
12	30	1 day, 15 h	0.50	0	−1.682	0	0.82	53.43
13	30	5	0.92	0	0	+1.682	1.25	36.42
14	30	5	0.08	0	0	−1.682	0.78	22.53
15	30	5	0.50	0	0	0	2.18	63.20
16	30	5	0.50	0	0	0	1.77	51.32
17	30	5	0.50	0	0	0	1.84	53.36
18	30	5	0.50	0	0	0	2.25	65.24
19	30	5	0.50	0	0	0	1.89	55.20
20	30	5	0.50	0	0	0	2.00	57.99