Novel insights into the anaerobic digestion of propionate via Syntrophobacter fumaroxidans and Geobacter sulfurreducens: Process and mechanism. (15th July 2021)

• Record Type: Journal Article
• Authors: Wang, Tao; Zhu, Gefu; Kuang, Bin; Jia, Jianbo; Liu, Changyu; Cai, Guanjing; Li, Chunxing
• Is Part Of: Water research. Volume 200(2021)
• Publication Date: 2021-07-15
• Subjects: Anaerobic digestion -- Propionate -- Syntrophism -- Syntrophobacter fumaroxidans -- Geobacter sulfurreducens -- Mechanism; Water -- Pollution -- Research -- Periodicals; 363.7394
• DOI: 10.1016/j.watres.2021.117270
• Languages: English
• ISSNs: 0043-1354

Abstract

Highlights: VFAs inhibit the efficiency of AD systems. S. fumaroxidans and G. sulfurreducens co-culture promotes propionate degradation. G. sulfurreducen strengthens the H2 and acetate consumption via DIET. Abstract: The accumulation of volatile fatty acids, particularly propionic acid, significantly inhibits the efficiency of the anaerobic digestion system. In propionate degradation metabolism, the unfavorable thermodynamics of syntrophic reactions, strict ecological niche of syntrophic priopionate oxidizing bacteria, and slow metabolic rate of methanogens are regarded as major limitations. In this study, Geobacter sulfurreducens was co-cultured with Syntrophobacter fumaroxidans in bioelelectrochemical cells to analyze the propionate degradation process, impact factor, mechanism metabolic pathways, and electron transfer comprehensively. The results revealed that the syntroph S. fumaroxidans and syntrophic partner G. sulfurreducens achieved more efficient propionate degradation than the control group, comprising S. fumaroxidans and methanogens. Moreover, the carbon resource concentration and pH were both significantly correlated with propionate degradation ( P < 0.01). The results further confirmed that G. sulfurreducen strengthened the consumption of H2 and acetate via direct interspecific electron transfer in propionate degradation. These findings indicate that G. sulfurreducens plays an unidentified functional role in propionate degradation. Graphical abstract: Image, graphical abstract