Engineering a wild-type diploid Saccharomyces cerevisiae strain for second-generation bioethanol production

Bioresources and Bioprocessing

Table 3 Metabolic characteristics of engineered S. cerevisiae strains in batch fermentations of sugars

	Strains	Medium^a	Fermentation device	Initial inoculum (g DCW L⁻¹)	Consumed xylose (g L⁻¹)	μ_max	Product yield (g g⁻¹ consumed sugars)					Specific consumption or production rate (g g⁻¹ DCW h⁻¹)^f
	Strains	Medium^a	Fermentation device	Initial inoculum (g DCW L⁻¹)	Consumed xylose (g L⁻¹)	μ_max	Biomass^b	Xylitol^c	Glycerol	Acetate	Ethanol^d	Xylose	Sugar^e	Ethanol
1	BSN3	YPX40	Fermentor	0.5	5.62	0.044	0.501	0	0	0	0.210	0.043	-	0.014
2	XH7	YPX40	Fermentor	0.5	40.54	0.141	0.136	0.008	0.019	0.000	0.480	0.569	-	0.310
3	BSN3	YPD80X40	Fermentor	0.5	16.71	0.190	0.110	0.121	0.046	0.033	0.406	0.037	0.382	0.169
4	XH7	YPD80X40	Fermentor	0.5	39.98	0.280	0.091	0.018	0.051	0.015	0.462	0.135	0.792	0.410
5	XH7	Hy1-YP	Shake flask	0.5	23.16	–	0.065	0.016	0.055	0.023	0.390	0.089	0.240	0.060
6	XH7	Hy1-Urea	Shake flask	0.5	18.74	–	0.020	0.013	0.048	0.027	0.371	0.096	0.235	0.080
7	XH7	Hy1-Urea	Shake flask	1.5	34.16	–	0.020	0.011	0.053	0.026	0.400	0.124	0.460	0.184
8	XHR11	Hy1-Urea	Shake flask	1.5	27.45	–	0.032	0.010	0.053	0.034	0.394	0.091	0.425	0.169
9	XH7	YPX40	Shake flask	0.5	41.34	–	–	0.004	0.014	0.003	0.435	0.763	-	0.314
10	XHR11	YPX40	Shake flask	0.5	21.60	–	–	0.002	0.018	0.012	0.374	0.358	-	0.124
11	LF1	YPX40	Shake flask	0.5	41.32	–	–	0.003	0.020	0.012	0.446	1.089	-	0.472
12	XH7	YPD80X40	Shake flask	0.5	33.35	–	–	0.024	0.045	0.016	0.452	0.193	1.057	0.487
13	XHR11	YPD80X40	Shake flask	0.5	25.37	–	–	0.014	0.037	0.012	0.462	0.128	0.913	0.425
14	LF1	YPD80X40	Shake flask	0.5	41.03	–	–	0.007	0.037	0.008	0.475	0.482	1.738	0.819
15	LF1	Hy1-Urea	Shake flask	1.5	36.43	0.034	0.028	0.001	0.045	0.006	0.413	0.227	0.801	0.334
16	LF1	Hy2-Urea	Shake flask	1.5	23.21	0.051	0.035	0	0	0	0.416	0.341	1.292	0.529

Data are the averages of independent triplicate cultivations. All standard errors were less than 5%. The physiological parameters were calculated at either the end of the fermentation or at the time xylose was depleted
^aThe medium was defined in “Methods” section
^bBiomass yield was calculated based on glucose for cultivation on mixed glucose and xylose or based on xylose for cultivation with xylose as the sole carbon source
^cXylitol yield was calculated based on consumed xylose
^dGlycerol, acetate and ethanol yields were calculated based on all consumed sugars
^eThe specific consumption rate for glucose and xylose in fermentation with mixed sugars
^f DCW dry cell weight; refers to biomass