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Electrogenic sulfide oxidation mediated by cable bacteria stimulates sulfate reduction in freshwater sediments.
ISME J. 2020 05; 14(5):1233-1246.IJ

Abstract

Cable bacteria are filamentous members of the Desulfobulbaceae family that oxidize sulfide with oxygen or nitrate by transferring electrons over centimeter distances in sediments. Recent studies show that freshwater sediments can support populations of cable bacteria at densities comparable to those found in marine environments. This is surprising since sulfide availability is presumably low in freshwater sediments due to sulfate limitation of sulfate reduction. Here we show that cable bacteria stimulate sulfate reduction in freshwater sediment through promotion of sulfate availability. Comparing experimental freshwater sediments with and without active cable bacteria, we observed a three- to tenfold increase in sulfate concentrations and a 4.5-fold increase in sulfate reduction rates when cable bacteria were present, while abundance and community composition of sulfate-reducing microorganisms (SRM) were unaffected. Correlation and ANCOVA analysis supported the hypothesis that the stimulation of sulfate reduction activity was due to relieve of the kinetic limitations of the SRM community through the elevated sulfate concentrations in sediments with cable bacteria activity. The elevated sulfate concentration was caused by cable bacteria-driven sulfide oxidation, by sulfate production from an indigenous sulfide pool, likely through cable bacteria-mediated dissolution and oxidation of iron sulfides, and by enhanced retention of sulfate, triggered by an electric field generated by the cable bacteria. Cable bacteria in freshwater sediments may thus be an integral component of a cryptic sulfur cycle and provide a mechanism for recycling of the scarce resource sulfate, stimulating sulfate reduction. It is possible that this stimulation has implication for methanogenesis and greenhouse gas emissions.

Authors+Show Affiliations

Department of Bioscience, Section for Microbiology, Aarhus University, Aarhus, Denmark. Center for Geomicrobiology, Aarhus University, Aarhus, Denmark.Department of Bioscience, Section for Microbiology, Aarhus University, Aarhus, Denmark. Center for Geomicrobiology, Aarhus University, Aarhus, Denmark. Center for Electromicrobiology, Aarhus University, Aarhus, Denmark. Department of Chemistry, Vrije Universiteit Brussel, Brussel, Belgium.Department of Bioscience, Section for Microbiology, Aarhus University, Aarhus, Denmark. Center for Geomicrobiology, Aarhus University, Aarhus, Denmark. Center for Electromicrobiology, Aarhus University, Aarhus, Denmark.Department of Bioscience, Section for Microbiology, Aarhus University, Aarhus, Denmark. Center for Geomicrobiology, Aarhus University, Aarhus, Denmark. Center for Electromicrobiology, Aarhus University, Aarhus, Denmark.Department of Bioscience, Section for Microbiology, Aarhus University, Aarhus, Denmark. nils.risgaard-petersen@bios.au.dk. Center for Geomicrobiology, Aarhus University, Aarhus, Denmark. nils.risgaard-petersen@bios.au.dk. Center for Electromicrobiology, Aarhus University, Aarhus, Denmark. nils.risgaard-petersen@bios.au.dk.

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

32042102

Citation

Sandfeld, Tobias, et al. "Electrogenic Sulfide Oxidation Mediated By Cable Bacteria Stimulates Sulfate Reduction in Freshwater Sediments." The ISME Journal, vol. 14, no. 5, 2020, pp. 1233-1246.
Sandfeld T, Marzocchi U, Petro C, et al. Electrogenic sulfide oxidation mediated by cable bacteria stimulates sulfate reduction in freshwater sediments. ISME J. 2020;14(5):1233-1246.
Sandfeld, T., Marzocchi, U., Petro, C., Schramm, A., & Risgaard-Petersen, N. (2020). Electrogenic sulfide oxidation mediated by cable bacteria stimulates sulfate reduction in freshwater sediments. The ISME Journal, 14(5), 1233-1246. https://doi.org/10.1038/s41396-020-0607-5
Sandfeld T, et al. Electrogenic Sulfide Oxidation Mediated By Cable Bacteria Stimulates Sulfate Reduction in Freshwater Sediments. ISME J. 2020;14(5):1233-1246. PubMed PMID: 32042102.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Electrogenic sulfide oxidation mediated by cable bacteria stimulates sulfate reduction in freshwater sediments. AU - Sandfeld,Tobias, AU - Marzocchi,Ugo, AU - Petro,Caitlin, AU - Schramm,Andreas, AU - Risgaard-Petersen,Nils, Y1 - 2020/02/10/ PY - 2019/08/01/received PY - 2020/01/30/accepted PY - 2020/01/27/revised PY - 2021/05/01/pmc-release PY - 2020/2/12/pubmed PY - 2020/10/30/medline PY - 2020/2/12/entrez SP - 1233 EP - 1246 JF - The ISME journal JO - ISME J VL - 14 IS - 5 N2 - Cable bacteria are filamentous members of the Desulfobulbaceae family that oxidize sulfide with oxygen or nitrate by transferring electrons over centimeter distances in sediments. Recent studies show that freshwater sediments can support populations of cable bacteria at densities comparable to those found in marine environments. This is surprising since sulfide availability is presumably low in freshwater sediments due to sulfate limitation of sulfate reduction. Here we show that cable bacteria stimulate sulfate reduction in freshwater sediment through promotion of sulfate availability. Comparing experimental freshwater sediments with and without active cable bacteria, we observed a three- to tenfold increase in sulfate concentrations and a 4.5-fold increase in sulfate reduction rates when cable bacteria were present, while abundance and community composition of sulfate-reducing microorganisms (SRM) were unaffected. Correlation and ANCOVA analysis supported the hypothesis that the stimulation of sulfate reduction activity was due to relieve of the kinetic limitations of the SRM community through the elevated sulfate concentrations in sediments with cable bacteria activity. The elevated sulfate concentration was caused by cable bacteria-driven sulfide oxidation, by sulfate production from an indigenous sulfide pool, likely through cable bacteria-mediated dissolution and oxidation of iron sulfides, and by enhanced retention of sulfate, triggered by an electric field generated by the cable bacteria. Cable bacteria in freshwater sediments may thus be an integral component of a cryptic sulfur cycle and provide a mechanism for recycling of the scarce resource sulfate, stimulating sulfate reduction. It is possible that this stimulation has implication for methanogenesis and greenhouse gas emissions. SN - 1751-7370 UR - https://www.unboundmedicine.com/medline/citation/32042102/Electrogenic_sulfide_oxidation_mediated_by_cable_bacteria_stimulates_sulfate_reduction_in_freshwater_sediments_ L2 - https://doi.org/10.1038/s41396-020-0607-5 DB - PRIME DP - Unbound Medicine ER -