Brewer’s spent grain (BSG) as the major byproduct in the brewing industry is a promising feedstock to produce value-added products such as volatile fatty acids (VFAs). Synergistic ball mill–enzymatic hydrolysis (BM-EH) process is an environmentally friendly pretreatment method for lignocellulosic materials before bioprocessing. This study investigated the potential of raw and BM-EH pretreated BSG feedstocks to produce VFAs through a direct thermophilic anaerobic fermentation process without introducing a methanogen inhibitor. The highest VFA concentration of over 30 g/L was achieved under the high-solid loading fermentation (HS) of raw BSG. The synergistic BM-EH pretreatment helps to increase the cellulose conversion to 70%. Under conventional low TS fermentation conditions, compared to the controlled sample, prolonged pretreatment of the BSG substrate resulted in increased VFA yields from 0.25 to 0.33 g/gVS, and butyric acid became dominant instead of acetic acid.
|State||Published - Jun 2023|
Bibliographical noteFunding Information:
This work was supported by the USDA National Institute of Food and Agriculture under project accession no. 1018315.
© 2023 by the authors.
- ball mill–enzymatic hydrolysis pretreatment
- brewer’s spent grain
- thermophilic anaerobic fermentation
- volatile fatty acid profile
ASJC Scopus subject areas
- Chemical Engineering (miscellaneous)
- Process Chemistry and Technology