Phenotypic selection of a wild Saccharomyces cerevisiae strain for simultaneous saccharification and co-fermentation of AFEX™ pretreated corn stover

Table 3 Summary of SSCF results on ACS using Y35 and 424A at two biomass solids loadings (6% glucan loading and 9% glucan loading) and at 30 or 35°C ^a

	Y35 (6%-30°C)	Y35 (6%-35°C)	424A (6%-30°C)	424A (6%-35°C)	Y35 (9%-30°C)	Y35 (9%-35°C)	424A (9%-30°C)	424A (9%-35°C)
Final xylose conc. (g/L)	10.9 ± 0.8	13.3 ± 2.5	5.4 ± 0.6	13.1 ± 1.4	22.70 ± 1.35	24.69 ± 1.27	17.2 ±0.8	25.2 ± 0.6
Xylitol (g/L)	4.7 ± 0.5	4.4 ± 1.0	0.4 ± 0.0	0.6 ± 0.2	2.9 ± 1.0	4.9 ± 1.4	0.0 ±0.0	0.4 ± 0.1
Glycerol (g/L)	5.4 ± 0.4	5.5 ± 0.2	5.9 ± 0.2	6.3 ± 0.5	7.4 ± 0.4	6.8 ± 0.6	7.5 ±0.4	7.7 ± 0.4
Final Ethanol conc. (g/L)	34.9 ± 0.8	34.6 ± 1.7	40.3 ± 0.2	37.3 ± 1.0	49.5 ± 2.9	51.3 ± 0.4	54.4 ±1.3	48.8 ± 1.7
Monomeric sugar conversion^b	72.5% ± 0.8%	73.7% ± 1%	71.8% ± 0.4%	73.6% ± 0.7%	68.7% ± 2.4%	71.7% ± 0.4%	69.8% ±1.5%	71.7% ± 1.7%
Sugar consumption^c	87.0% ± 1.1%	84.9% ± 3.1%	93.6% ± 0.9%	84.6% ± 1.7%	80.8% ± 1.9%	80.3% ± 0.8%	84.7% ±0.7%	74.0% ± 1.5%
Ethanol volumetric productivity (g/L/h), 48 h^d	0.52 ± 0.02	0.56 ± 0.00	0.63 ±0.01	0.65 ±0.01	0.69 ±0.02	0.76 ± 0.02	0.78 ± 0.02	0.82 ± 0.02

^aSSCF experiments were carried out in 250 ml baffled flasks with working weight of 100 g. Shaking speed, temperature and initial pH were 180 rpm, 30°C and 5.5, respectively.
^bMonomeric sugar conversion was calculated based on the ethanol concentration and the remaining monomeric glucose and xylose in the fermentation broth after 168 h with the assumption of ethanol metabolic yield the same as SHF.
^cSugar consumption was calculated based on available monomeric glucose and xylose for fermentation.
^dEthanol volumetric productivity was based on the 48 h results.

ISSN: 2731-3654