Bioaugmentation strategy for overcoming ammonia inhibition during biomethanation of a protein-rich substrate. (September 2019)

• Record Type: Journal Article
• Authors: Tian, Hailin; Mancini, Enrico; Treu, Laura; Angelidaki, Irini; Fotidis, Ioannis A.
• Is Part Of: Chemosphere. Volume 231(2019)
• Page Start: 415
• Page End: 422
• Publication Date: 2019-09
• Subjects: Methane -- Ammonia inhibition -- Microbial community -- Methanoculleus bourgensis -- Hydrogen partial pressure; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2019.05.140
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: High ammonia levels inhibit anaerobic digestion (AD) process and bioaugmentation with ammonia tolerant methanogenic culture is proposed to alleviate ammonia inhibition. In the current study, hydrogenotrophic Methanoculleus bourgensis was bioaugmented in an ammonia-inhibited continuous reactor fed mainly with microalgae (a protein-rich biomass), at extreme ammonia levels (i.e. 11 g NH4 + -N L −1 ). The results showed 28% increase in methane production immediately after bioaugmentation. Moreover, volatile fatty acids decreased rapidly from more than 5 g L −1 to around 1 g L −1, with a fast reduction in propionate concentration. High throughput 16s rRNA gene sequencing demonstrated that the bioaugmented M. bourgensis doubled its relative abundance after bioaugmentation. "Microbiological domino effect", triggered by the bioaugmented M. bourgensis establishing a newly efficient community, was proposed as the working mechanism of the successful bioaugmentation. Additionally, a strong aceticlastic methanogenesis was found at the end of the experiment evidenced by the dominant presence of Methanosarcina soligelidi and the low abundance of syntrophic acetate oxidising bacteria at the final period. Overall, for the first time, this study proved the positive effect of bioaugmentation on ammonia inhibition alleviation of the microalgae-dominating fed reactor, paving the way of efficient utilization of other protein-rich substrates in the future. Graphical abstract: Image 1 Highlights: Bioaugmentation alleviated ammonia inhibition of a reactor fed with microalgae. Bioaugmented M. bourgensis increased methane yield by 28% and decreased VFA by 80%. Reduction of hydrogen pressure and propionate is crucial in alleviating inhibition. The bioaugmentation success lies on the triggered "microbiological domino effect". M. soligelidi was the dominant methanogen three HRTs after bioaugmentation.