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15:19
Development of Sulfidogenic Sludge from Marine Sediments and Trichloroethylene Reduction in an Upflow Anaerobic Sludge Blanket Reactor
Published on: October 15, 2015
Metabolic interactions in methanogenic and sulfate-reducing bioreactors
A J M Stams1, C M Plugge, F A M de Bok
1Laboratory of Microbiology, Wageningen University, Hesselink van Suchtelenweg 4, 6703 CT Wageningen, The Netherlands. fons.stams@wur.nl
Summary
In methanogenic environments, syntrophic bacteria and archaea degrade organic acids. Sulfate-reducing bacteria compete for resources, potentially inhibiting methane production.
Area of Science:
- Microbiology
- Environmental Science
- Biogeochemistry
Background:
- Methanogenic environments produce methane from organic matter breakdown when electron acceptors are scarce.
- Syntrophic consortia of acetogenic bacteria and methanogenic archaea degrade organic acids.
- Methanogen hydrogen consumption is crucial for acetogenic conversion of organic acids.
Purpose of the Study:
- To investigate the impact of sulfate on syntrophic consortia degrading propionate and butyrate.
- To understand the competitive interactions between sulfate-reducing bacteria and methanogenic archaea.
Main Methods:
- Cultivation of syntrophic cocultures on propionate and butyrate.
- Analysis of microbial competition in the presence of sulfate.
- Comparison of growth rates and substrate utilization.
Main Results:
- Sulfate-reducing bacteria compete effectively with methanogens for hydrogen.
- Competition for acetate and fatty acids (propionate, butyrate) occurs between sulfate-reducers and syntrophic consortia.
- Sulfate-reducing bacteria exhibit faster growth on propionate and butyrate compared to syntrophic consortia.
Conclusions:
- Sulfate presence significantly impacts methanogenic degradation pathways.
- Sulfate-reducing bacteria can outcompete methanogens and acetogens, potentially inhibiting methane formation.
- Acetate availability influences the competitive balance between sulfate-reducers and methanogens.
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