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Adaptation at the Extremes of Life: Experimental Evolution with the Extremophile Archaeon Sulfolobus acidocaldarius
Published on: June 14, 2024
Metabolic flexibility of sulfate-reducing bacteria
Caroline M Plugge1, Weiwen Zhang, Johannes C M Scholten
1Laboratory of Microbiology, Wageningen University Wageningen, Netherlands.
Frontiers in Microbiology
|July 8, 2011
Summary
Dissimilatory sulfate-reducing prokaryotes (SRB) are vital anaerobic bacteria in global carbon and sulfur cycles. This review explores their diverse metabolic strategies, including sulfidogenic and acetogenic pathways, enhancing survival in varied environments.
Area of Science:
- Microbiology
- Environmental Science
- Biogeochemistry
Background:
- Dissimilatory sulfate-reducing prokaryotes (SRB) are ubiquitous anaerobic bacteria crucial for global carbon and sulfur cycling.
- In marine sediments, SRB drive organic mineralization, with sulfate reduction occurring in upper layers and methanogenesis in deeper, sulfate-depleted zones.
- SRB exhibit diverse metabolic capabilities, including sulfidogenic and acetogenic/hydrogenogenic pathways, enabling survival in environments with fluctuating electron acceptor availability.
Purpose of the Study:
- To review the physiology and metabolic modes of SRB.
- To understand the role of SRB in different ecosystems, particularly marine and freshwater sediments.
- To elucidate the interactions between SRB and methanogens in organic matter degradation.
Main Methods:
- Literature review of SRB physiology and metabolism.
- Analysis of SRB roles in marine and freshwater sediment environments.
- Evaluation of metabolic flexibility in response to environmental conditions.
Main Results:
- SRB play a significant role in organic mineralization, accounting for up to 50% in coastal marine sediments.
- SRB can adopt sulfidogenic or acetogenic/hydrogenogenic lifestyles, adapting to the availability of electron acceptors like sulfate.
- In sulfate-limited environments, SRB can ferment organic acids and alcohols, potentially interacting with methanogens.
Conclusions:
- SRB possess adaptable metabolic strategies that are key to their survival and ecological importance.
- SRB and methanogens often complement each other in the degradation of organic matter in various aquatic ecosystems.
- Understanding SRB metabolism is crucial for comprehending biogeochemical cycles and microbial ecology.
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