Temperature and solids retention time control microbial population dynamics and volatile fatty acid production in replicated anaerobic digesters.

Vanwonterghem, Inka, Jensen, Paul D., Rabaey, Korneel and Tyson, Gene W. (2015) Temperature and solids retention time control microbial population dynamics and volatile fatty acid production in replicated anaerobic digesters.. Scientific Reports, 5 . doi:10.1038/srep08496


Author Vanwonterghem, Inka
Jensen, Paul D.
Rabaey, Korneel
Tyson, Gene W.
Title Temperature and solids retention time control microbial population dynamics and volatile fatty acid production in replicated anaerobic digesters.
Journal name Scientific Reports   Check publisher's open access policy
ISSN 2045-2322
Publication date 2015-02-16
Year available 2015
Sub-type Article (original research)
DOI 10.1038/srep08496
Open Access Status DOI
Volume 5
Total pages 8
Place of publication London, United Kingdom
Publisher Nature Publishing Group
Language eng
Subject 1000 General
Abstract Anaerobic digestion is a widely used technology for waste stabilization and generation of biogas, and has recently emerged as a potentially important process for the production of high value volatile fatty acids (VFAs) and alcohols. Here, three reactors were seeded with inoculum from a stably performing methanogenic digester, and selective operating conditions (376 degrees C and 55 degrees C; 12 day and 4 day solids retention time) were applied to restrict methanogenesis while maintaining hydrolysis and fermentation. Replicated experiments performed at each set of operating conditions led to reproducible VFA production profiles which could be correlated with specific changes in microbial community composition. The mesophilic reactor at short solids retention time showed accumulation of propionate and acetate (42 +/- 2% and 15 +/- 6% of CODhydrolyzed, respectively), and dominance of Fibrobacter and Bacteroidales. Acetate accumulation >50% of CODhydrolyzed) was also observed in the thermophilic reactors, which were dominated by Clostridium. Under all tested conditions, there was a shift from acetoclastic to hydrogenotrophic methanogenesis, and a reduction in methane production by. 50% of CODhydrolyzed. Our results demonstrate that shortening the SRT and increasing the temperature are effective strategies for driving microbial communities towards controlled production of high levels of specific volatile fatty acids.
Formatted abstract
Anaerobic digestion is a widely used technology for waste stabilization and generation of biogas, and has recently emerged as a potentially important process for the production of high value volatile fatty acids (VFAs) and alcohols. Here, three reactors were seeded with inoculum from a stably performing methanogenic digester, and selective operating conditions (37°C and 55°C; 12 day and 4 day solids retention time) were applied to restrict methanogenesis while maintaining hydrolysis and fermentation. Replicated experiments performed at each set of operating conditions led to reproducible VFA production profiles which could be correlated with specific changes in microbial community composition. The mesophilic reactor at short solids retention time showed accumulation of propionate and acetate (42 ± 2% and 15 ± 6% of CODhydrolyzed, respectively), and dominance of Fibrobacter and Bacteroidales. Acetate accumulation (>50% of CODhydrolyzed) was also observed in the thermophilic reactors, which were dominated by Clostridium. Under all tested conditions, there was a shift from acetoclastic to hydrogenotrophic methanogenesis, and a reduction in methane production by >50% of CODhydrolyzed. Our results demonstrate that shortening the SRT and increasing the temperature are effective strategies for driving microbial communities towards controlled production of high levels of specific volatile fatty acids.
Keyword Applied microbiology
Microbial ecology
Q-Index Code C1
Q-Index Status Confirmed Code
Grant ID DP1093175
Institutional Status UQ
Additional Notes Article number: 8496

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2016 Collection
School of Chemistry and Molecular Biosciences
Advanced Water Management Centre Publications
 
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Created: Fri, 20 Feb 2015, 20:56:59 EST by Mrs Louise Nimwegen on behalf of School of Chemistry & Molecular Biosciences