Derivation of volatile fatty acid from crop residues digestion using a rumen membrane bioreactor: A feasibility study

• Published in: Bioresource technology 2020-09, Vol.312, p.123571-123571, Article 123571
• Main Authors: Nguyen, Anh Q., Nguyen, Luong N., Johir, Md Abu Hasan, Ngo, Huu-Hao, Chaves, Alex V., Nghiem, Long D.
• Format: Article
• Language: English
• Subjects: Anaerobic digestion; Lignocellulosic biomass; Membrane bioreactor; Rumen microbial community; Volatile fatty acids
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2020.123571

•A rumen membrane bioreactor (MBR) was developed to derive VFA from crop residues.•VFA yield of 438 mg/g substrate per day was achieved in continuous operation.•Acetic and propionic acids accounted for >80% of the total VFA produced.•The produced VFA was continuously transferred to a clean matrix by UF membrane.•Changes in the microbial community did not impact the rumen-MBR’s performance. This study evaluates the feasibility of a novel rumen membrane bioreactor (rumen MBR) to produce volatile fatty acids (VFA) from crop residues (i.e. lignocellulosic biomass). Rumen MBR can provide a sustainable route for VFA production by mimicking the digestive system of ruminant animals. Rumen fluid was inoculated in a reactor coupled with ultrafiltration (UF) membrane and fed with maize silage and concentrate feed at 60:40% (w/w). Continuous VFA production was achieved at an average daily yield of 438 mg VFA/g substrate. The most abundant VFA were acetic (40–80%) and propionic (10–40%) acids. The majority (73 ± 15%) of produced VFA was transferred through the UF membrane. Shifts in dominant rumen microbes were observed upon the transition from in vivo to in vitro environment and during reactor operation, however, stable VFA yield was maintained for 35 days, providing the first proof-of-concept of a viable rumen MBR.