Process intensification through microbial strain evolution: mixed glucose-xylose fermentation in wheat straw hydrolyzates by three generations of recombinant Saccharomyces cerevisiae

Table 4 Physiological parameters of strains BP10001, IBB10A02 and IBB10B05 obtained from mixed glucose-xylose fermentation in 15% hydrolyzate

Parameter	BP10001	IBB10A02	IBB10B05
q_Glucose (g/g_CDW/h)^a1	2.81 ± 0.04	1.71 ± 0.05	2.90 ± 0.22
q_{X ylose} (g/g_CDW/h)	0.02 ± 0.01	0.23 ± 0.01	0.35 ± 0.02
μ_max^a2	0.10 ± 0.01	0.10 ± 0.01	0.19 ± 0.01
Y_Ethanol (g/g)	0.40	0.39	0.39
(Y_{Ethanol/available sugars} (g/g))^b	(0.13)	(0.38)	(0.38)
Y_Glycerol (g/g)	0.10	0.08	0.08
Y_Xylitol (g/g)	0.04	0.08	0.08
Y_Acetate (g/g)	0.04	0.04	0.04
Y_BM (g/g)	0.05	0.04	0.06
C-recovery (%)	103 ± 1	101 ± 1	104 ± 1

Data was obtained from two independent fermentations, mean errors of product coefficients were always below 14%. Fermentation time courses are shown in Figure 3. Fermentation in 15% hydrolyzate: glucose to xylose ratio of approximately 2.^a Determined in the first ^a1 3.5 h and ^a2 6 hours of fermentation;^bY_{Ethanol/available sugars} = c (Ethanol produced in 50 h of fermentation)/c (Available glucose and xylose).

ISSN: 2731-3654