Long-term preserved and rapidly revived methanogenic cultures: Microbial dynamics and preservation mechanisms. (1st August 2020)

• Record Type: Journal Article
• Authors: Yan, Miao; Fotidis, Ioannis A.; Jéglot, Arnaud; Treu, Laura; Tian, Hailin; Palomo, Alejandro; Zhu, Xinyu; Angelidaki, Irini
• Is Part Of: Journal of cleaner production. Volume 263(2020)
• Publication Date: 2020-08-01
• Subjects: Ammonia tolerant -- Revival rate -- Cell entrapment -- Gel preservation -- Methanosarcina soligelidi; Factory and trade waste -- Management -- Periodicals; Manufactures -- Environmental aspects -- Periodicals; Déchets industriels -- Gestion -- Périodiques; Usines -- Aspect de l'environnement -- Périodiques; 628.5
• DOI: 10.1016/j.jclepro.2020.121577
• Languages: English
• ISSNs: 0959-6526

Abstract

Abstract: Bioaugmentation with specialized inocula has been proven a feasible way to remediate under-performing anaerobic digestion (AD) processes. However, a major bottleneck for successful and cost-effective bioaugmentation is the lack of ready-to-use, specialized methanogenic cultures when required. The reason is the slow growth of the anaerobic consortia and the high cost of maintaining them active in the necessary amounts for successful bioaugmentation applications. This study offers an effective procedure where customized AD inocula could be preserved and used on-demand for remediation of ammonia inhibited AD reactors. Additionally, it introduces the biological and physicochemical mechanisms that render the long-term preservation of the AD inocula possible. Specifically, two different preservation carriers (i.e. agar gel and liquid basic anaerobic medium) were assessed at two different temperatures (i.e. 4 °C and 24 °C) using an ammonia tolerant methanogenic consortium. The results from methane production, lag-phase, maximum methane production rate and cell viability indicate that the consortium preserved for 168 days in agar gel at 24 °C performed best compared to the other tested preservation conditions. Meanwhile, 16S rRNA sequencing analysis indicated that Methanosarcina soligelidi and Methanoculleus palmolei shown a high revival rate and metabolic activity after long-term preservation. Thus, this successful long-term preservation method of ready-to-use AD consortia could render the successful bioaugmentation in full-scale biogas reactors economically possible in the near future. Graphical abstract: Image 1 Highlights: Cells in agar gel was successful preserved for 168 days at 24 °C. Preservation carrier and temperature were key for cell viability and performance. M. soligelidi and M. palmolei were active after the long-term preservation. A novel preservation strategy of ready-to-use methanogenic consortia was created.