Production of butyric acid from acid hydrolysate of corn husk in fermentation by Clostridium tyrobutyricum: kinetics and process economic analysis

Table 2 Comparison between free-cell and immobilized cell fermentations for butyric acid production from different carbon sources

Substrate	Glucose	Xylose			Mixture^a	CHH
Fermentation mode	Free-cell	FBB	Free-cell	FBB	FBB	FBB
Total sugar consumed (g L⁻¹)	113.80 ± 0.12	119.12 ± 0.25	103.82 ± 0.34	122.15 ± 0.13	133.95 ± 0.32	53.27 ± 0.21
Butyrate conc. (g L⁻¹)	37.95 ± 0.02	54.12 ± 0.02	32.96 ± 0.05	50.43 ± 0.07	50.37 ± 0.04	20.75 ± 0.65
Butyrate yield (g g⁻¹)	0.33 ± 0.03	0.45 ± 0.02	0.32 ± 0.04	0.41 ± 0.03	0.38 ± 0.02	0.39 ± 0.02
Butyrate productivity (g L⁻¹ h⁻¹)	0.29 ± 0.02	0.39 ± 0.01	0.25 ± 0.01	0.34 ± 0.03	0.34 ± 0.03	0.42 ± 0.06
Acetate conc. (g L⁻¹)	4.83 ± 0.03	4.31 ± 0.04	3.50 ± 0.21	3.94 ± 0.04	4.08 ± 0.02	4.13 ± 0.22
Acetate yield (g g⁻¹)	0.04 ± 0.02	0.04 ± 0.01	0.03 ± 0.01	0.03 ± 0.01	0.03 ± 0.02	0.08 ± 0.01
Butyrate/Acetate (g g⁻¹)	7.86 ± 0.02	12.56 ± 0.04	9.41 ± 0.03	12.80 ± 0.07	12.30 ± 0.03	5.02 ± 0.24

Each value was the average of three replicate runs reported as mean ± standard deviation
CHH corn husk hydrolysate
^aMixture: 28.06 g L⁻¹ glucose, 29.22 g L⁻¹ xylose

ISSN: 2731-3654