RT Journal Article
T1 Optimising butyric and lactic acid yield from xylose by adjusting pH
A1 Iglesias Riobó, Juan
A1 Mauricio Iglesias, Miguel
A1 Carballa Arcos, Marta
K1 Carbohydrates
K1 Carboxylate biorefinery
K1 Medium-chain fatty acid precursors
K1 Mixed-culture anaerobic fermentation
K1 Volatile fatty acids
AB This work studies the pH effect in xylose mixed culture fermentation, focusing on lactic and butyric acid production. Batch tests showed a complete substrate consumption at slightly acidic (pH 6) and alkaline conditions (pH 8), but a great inhibition of xylose conversion was observed at pH 4. Acetic acid was the only product at pH 8, while at pH 6, butyric and propionic acids were quantified as well with a large proportion of unidentified compounds. Continuous reactor operation showed that changes within the acidic pH range (pH 4.5 to pH 6) affect the acidification degree but not the product distribution, reaching the maximum butyric acid yield (0.38 Cmol/Cmol-s) at pH 5, while lactic acid was only detected when xylose conversion or butyric acid concentration dropped. Batch tests demonstrated that butyric acid was not inhibitory for xylose or lactic acid conversion and that the main product of lactic acid fermentation was butyric acid. Although pH is an essential variable steering the fermentation yield and selectivity, this study demonstrates that it must be combined with other operational conditions in order to obtain a stable production of lactic and butyric acids.
PB Elsevier
YR 2024
FD 2024
LK http://hdl.handle.net/10347/34536
UL http://hdl.handle.net/10347/34536
LA eng
NO Industrial Crops and Products Volume 220 , 15 November 2024, 119206
NO This research was funded by the Spanish Government through the CELL4CHEM project (PCI2021-121989, ERACoBioTech 3rd call). The authors belong to a Galician Competitive Research Group (ED431C-2021/37).
DS Minerva
RD 28 abr 2026