High rejection rate of polysaccharides by microfiltration benefits Christensenella minuta and acetic acid production in an anaerobic membrane bioreactor for sludge fermentation

• Published in: Bioresource technology Vol. 282; pp. 197 - 201
• Main Authors: Gao, Xiaole, Zhang, Qianqian, Zhu, Hongtao
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.06.2019
• Subjects: Anaerobic digestion; Christensenella minuta; Membrane bioreactor; Microbial community; Volatile fatty acids; Christensenella minuta; Membrane bioreactor; Volatile fatty acids; Anaerobic digestion; Microbial community
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2019.03.015

•First report of C. minuta becoming the dominant species after MF membrane applied.•Other dominant sugar-fermenting genera like Parabacteroides decreased.•The MF membrane had a higher retention rate for polysaccharides than protein.•Total VFAs, mainly acetic acid, increased by one third after MF membrane applied. Substrates, the microbial community, and volatile fatty acids (VFAs) are interacting factors in anaerobic fermentation. In this paper, a microfiltration membrane was installed in a conventional reactor for sludge anaerobic fermentation, and changes in the VFA composition and the microbial community structure after the application were monitored. The membrane rejected much more polysaccharide than protein. VFA production, mainly acetic acid, was greatly enhanced by the membrane separation. The glycolytic species Christensenella minuta was significantly enriched. The explanation was inferred to be the higher retention rate of polysaccharide compared with proteins by the microfiltration. However, surprisingly, another polysaccharide using genus, Parabacteroides, did not benefit from the application of the membrane separation, suggesting more complicated mechanisms might be involved.