SSF of steam-pretreated wheat straw with the addition of saccharified or fermented wheat meal in integrated bioethanol production

Table 3 Substrate, product and by-product concentrations (c) and yields (Y) obtained after 120 hours of SSCF with SWM addition

Configuration	c_glu	c_xyl	c_EtoH	c_glycerol	Y_glycerol/glu	c_xylitol	Y_xylitol	Xyl cons.	EtOH prod. rate	Y_EtOH/glu		Y_EtOH/glu+xyl
	g/L	g/L	g/L	g/L	%^a	g/L	%^b	%^c	g/L/h^d	%	g/g^a	%	g/g^e
A^SSF Batch	3.5	17.9	59.5	3.8	3.0	2.0	82	9	0.98	95	0.49	75	0.38
A^SSCF Batch	3.5	14.1	56.8	8.0	6.3	1.2	20	22	1.86	87	0.44	72	0.37
A^SSCF Fed-batch I	0.0	11.6	60.0	4.3	3.4	1.0	12	31	0.57	92	0.47	76	0.39
A^SSCF Fed batch II	0.0	14.5	58.8	3.5	2.7	1.0	17	21	0.86	90	0.46	74	0.38

The experiments were performed using the xylose-fermenting S. cerevisiae strain KE6-12 (Mean values are given for the reference SSF experiment using baker’s yeast: the standard deviation was less than 2%), glu: glucose, xyl: xylose, EtOH: ethanol.
^a Based on total amount of glucose added to SSF/SSCF.
^b Based on consumed xylose.
^c Based on total amount of xylose added to SSF/SSCF.
^d Calculated for the first 8 hours.
^e Based on total amount of glucose and xylose added to SSF/SSCF.

ISSN: 2731-3654