title: Performance of batch, fed-batch, and continuous A-B-E fermentation with pH-control.
abstract: Batch, fed-batch, and continuous A-B-E fermentations were conducted and compared with pH controlled at 4.5, the optimal range for solvent production. While the batch mode provides the highest solvent yield, the continuous mode was preferred in terms of butanol yield and productivity. The highest butanol yield and productivity found in the continuous fermentation at dilution rate of 0.1h(-1) were 0.21 g-butanol/g-glucose and 0.81 g/L/h, respectively. In the continuous and fed-batch fermentation, the time needed for passing acidogenesis to solventogenesis was an intrinsic hindrance to higher butanol productivity. Therefore, a low dilution rate is suggested for the continuous A-B-E fermentation, while the fed-batch mode is not suggested for solvent production. While 3:6:1 ratio of acetone, butanol, and ethanol is commonly observed from A-B-E batch fermentation by Clostridium acetobutylicum when the pH is uncontrolled, up to 94% of the produced solvent was butanol in the chemostat with pH controlled at 4.5.
authors.affiliation: Department of Chemical, Materials and Biomolecular Engineering, University of Connecticut, Storrs, CT 06269, USA.
authors.forename: Si-Yu
authors.initials: SY
authors.lastname: Li
authors.forename: Ranjan
authors.initials: R
authors.lastname: Srivastava
authors.forename: Steven L
authors.initials: SL
authors.lastname: Suib
authors.forename: Yi
authors.initials: Y
authors.lastname: Li
authors.forename: Richard S
authors.initials: RS
authors.lastname: Parnas
mesh_terms: D000096:Acetone / Q000378:metabolism*; D056804:Biofuels; D001709:Biotechnology / Q000379:methods*; D000440:Butanols / Q000378:metabolism*; D002849:Chromatography, Gas; D046969:Clostridium acetobutylicum / Q000378:metabolism / Q000502:physiology*; D046970:Clostridium beijerinckii / Q000378:metabolism / Q000502:physiology*; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation / Q000502:physiology*; D006863:Hydrogen-Ion Concentration; D013053:Spectrophotometry
chemical_list: D056804:Biofuels; D000440:Butanols; D000096:Acetone; D000431:Ethanol