High-rate, high temperature acetotrophic methanogenesis governed by a three population consortium in anaerobic bioreactors

Ho, Dang, Jensen, Paul, Gutierrez-Zamora, Maria-Luisa, Beckmann, Sabrina, Manefield, Mike and Batstone, Damien (2016) High-rate, high temperature acetotrophic methanogenesis governed by a three population consortium in anaerobic bioreactors. PLoS ONE, 11 8: . doi:10.1371/journal.pone.0159760


Author Ho, Dang
Jensen, Paul
Gutierrez-Zamora, Maria-Luisa
Beckmann, Sabrina
Manefield, Mike
Batstone, Damien
Title High-rate, high temperature acetotrophic methanogenesis governed by a three population consortium in anaerobic bioreactors
Journal name PLoS ONE   Check publisher's open access policy
ISSN 1932-6203
Publication date 2016-08-04
Sub-type Article (original research)
DOI 10.1371/journal.pone.0159760
Open Access Status DOI
Volume 11
Issue 8
Total pages 13
Place of publication San Francisco, CA, United States
Publisher Public Library of Science
Language eng
Subject 1300 Biochemistry, Genetics and Molecular Biology
1100 Agricultural and Biological Sciences
Abstract A combination of acetate oxidation and acetoclastic methanogenesis has been previously identified to enable high-rate methanogenesis at high temperatures (55 to 65° C), but this capability had not been linked to any key organisms. This study combined RNA-stable isotope probing on 13C-labelled acetate and 16S amplicon sequencing to identify the active micro-organisms involved in high-rate methanogenesis. Active biomass was harvested from three bench-scale thermophilic bioreactors treating waste activated sludge at 55, 60 and 65° C, and fed with 13-C labelled and12 C-unlabelled acetate. Acetate uptake and cumulative methane production were determined and kinetic parameters were estimated using model-based analysis. Pyrosequencing performed on13 C- enriched samples indicated that organisms accumulating labelled carbon were Coprothermobacter (all temperatures between 55 and 65° C), acetoclastic Methanosarcina (55 to 60° C) and hydrogenotrophic Methanothermobacter (60 to 65° C). The increased relative abundance of Coprothermobacter with increased temperature corresponding with a shift to syntrophic acetate oxidation identified this as a potentially key oxidiser. Methanosarcina likely acts as both a hydrogen utilising and acetoclastic methanogen at 55° C, and is replaced by Methanothermobacter as a hydrogen utiliser at higher temperatures.
Formatted abstract
A combination of acetate oxidation and acetoclastic methanogenesis has been previously identified to enable high-rate methanogenesis at high temperatures (55 to 65° C), but this capability had not been linked to any key organisms. This study combined RNA-stable isotope probing on 13C-labelled acetate and 16S amplicon sequencing to identify the active micro-organisms involved in high-rate methanogenesis. Active biomass was harvested from three bench-scale thermophilic bioreactors treating waste activated sludge at 55, 60 and 65° C, and fed with 13-C labelled and 12C-unlabelled acetate. Acetate uptake and cumulative methane production were determined and kinetic parameters were estimated using model-based analysis. Pyrosequencing performed on 13C- enriched samples indicated that organisms accumulating labelled carbon were Coprothermobacter (all temperatures between 55 and 65° C), acetoclastic Methanosarcina (55 to 60° C) and hydrogenotrophic Methanothermobacter (60 to 65° C). The increased relative abundance of Coprothermobacter with increased temperature corresponding with a shift to syntrophic acetate oxidation identified this as a potentially key oxidiser. Methanosarcina likely acts as both a hydrogen utilising and acetoclastic methanogen at 55° C, and is replaced by Methanothermobacter as a hydrogen utiliser at higher temperatures.
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
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