Details
| Original language | English |
|---|---|
| Pages (from-to) | 1954-1966 |
| Number of pages | 13 |
| Journal | ISME J |
| Volume | 10 |
| Issue number | 8 |
| Publication status | Published - 1 Aug 2016 |
Abstract
Syntrophic bacteria drive the anaerobic degradation of certain fermentation products (e.g., butyrate, ethanol, propionate) to intermediary substrates (e.g., H 2, formate, acetate) that yield methane at the ecosystem level. However, little is known about the in situ activities and identities of these syntrophs in peatlands, ecosystems that produce significant quantities of methane. The consumption of butyrate, ethanol or propionate by anoxic peat slurries at 5 and 15 °C yielded methane and CO 2 as the sole accumulating products, indicating that the intermediates H 2, formate and acetate were scavenged effectively by syntrophic methanogenic consortia. 16S rRNA stable isotope probing identified novel species/strains of Pelobacter and Syntrophomonas that syntrophically oxidized ethanol and butyrate, respectively. Propionate was syntrophically oxidized by novel species of Syntrophobacter and Smithella, genera that use different propionate-oxidizing pathways. Taxa not known for a syntrophic metabolism may have been involved in the oxidation of butyrate (Telmatospirillum-related) and propionate (unclassified Bacteroidetes and unclassified Fibrobacteres). Gibbs free energies (ΔGs) for syntrophic oxidations of ethanol and butyrate were more favorable than ΔGs for syntrophic oxidation of propionate. As a result of the thermodynamic constraints, acetate transiently accumulated in ethanol and butyrate treatments but not in propionate treatments. Aceticlastic methanogens (Methanosarcina, Methanosaeta) appeared to outnumber hydrogenotrophic methanogens (Methanocella, Methanoregula), reinforcing the likely importance of aceticlastic methanogenesis to the overall production of methane. ΔGs for acetogenesis from H 2 to CO 2 approximated to -20 kJ mol -1 when acetate concentrations were low, indicating that acetogens may have contributed to the flow of carbon and reductant towards methane.
ASJC Scopus subject areas
- Immunology and Microbiology(all)
- Microbiology
- Agricultural and Biological Sciences(all)
- Ecology, Evolution, Behavior and Systematics
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In: ISME J, Vol. 10, No. 8, 01.08.2016, p. 1954-1966.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Peat: home to novel syntrophic species that feed acetate- and hydrogen-scavenging methanogens
AU - Schmidt, O.
AU - Hink, L.
AU - Horn, M. A.
AU - Drake, H. L.
N1 - Publisher Copyright: © 2016 International Society for Microbial Ecology All rights reserved. Copyright: Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2016/8/1
Y1 - 2016/8/1
N2 - Syntrophic bacteria drive the anaerobic degradation of certain fermentation products (e.g., butyrate, ethanol, propionate) to intermediary substrates (e.g., H 2, formate, acetate) that yield methane at the ecosystem level. However, little is known about the in situ activities and identities of these syntrophs in peatlands, ecosystems that produce significant quantities of methane. The consumption of butyrate, ethanol or propionate by anoxic peat slurries at 5 and 15 °C yielded methane and CO 2 as the sole accumulating products, indicating that the intermediates H 2, formate and acetate were scavenged effectively by syntrophic methanogenic consortia. 16S rRNA stable isotope probing identified novel species/strains of Pelobacter and Syntrophomonas that syntrophically oxidized ethanol and butyrate, respectively. Propionate was syntrophically oxidized by novel species of Syntrophobacter and Smithella, genera that use different propionate-oxidizing pathways. Taxa not known for a syntrophic metabolism may have been involved in the oxidation of butyrate (Telmatospirillum-related) and propionate (unclassified Bacteroidetes and unclassified Fibrobacteres). Gibbs free energies (ΔGs) for syntrophic oxidations of ethanol and butyrate were more favorable than ΔGs for syntrophic oxidation of propionate. As a result of the thermodynamic constraints, acetate transiently accumulated in ethanol and butyrate treatments but not in propionate treatments. Aceticlastic methanogens (Methanosarcina, Methanosaeta) appeared to outnumber hydrogenotrophic methanogens (Methanocella, Methanoregula), reinforcing the likely importance of aceticlastic methanogenesis to the overall production of methane. ΔGs for acetogenesis from H 2 to CO 2 approximated to -20 kJ mol -1 when acetate concentrations were low, indicating that acetogens may have contributed to the flow of carbon and reductant towards methane.
AB - Syntrophic bacteria drive the anaerobic degradation of certain fermentation products (e.g., butyrate, ethanol, propionate) to intermediary substrates (e.g., H 2, formate, acetate) that yield methane at the ecosystem level. However, little is known about the in situ activities and identities of these syntrophs in peatlands, ecosystems that produce significant quantities of methane. The consumption of butyrate, ethanol or propionate by anoxic peat slurries at 5 and 15 °C yielded methane and CO 2 as the sole accumulating products, indicating that the intermediates H 2, formate and acetate were scavenged effectively by syntrophic methanogenic consortia. 16S rRNA stable isotope probing identified novel species/strains of Pelobacter and Syntrophomonas that syntrophically oxidized ethanol and butyrate, respectively. Propionate was syntrophically oxidized by novel species of Syntrophobacter and Smithella, genera that use different propionate-oxidizing pathways. Taxa not known for a syntrophic metabolism may have been involved in the oxidation of butyrate (Telmatospirillum-related) and propionate (unclassified Bacteroidetes and unclassified Fibrobacteres). Gibbs free energies (ΔGs) for syntrophic oxidations of ethanol and butyrate were more favorable than ΔGs for syntrophic oxidation of propionate. As a result of the thermodynamic constraints, acetate transiently accumulated in ethanol and butyrate treatments but not in propionate treatments. Aceticlastic methanogens (Methanosarcina, Methanosaeta) appeared to outnumber hydrogenotrophic methanogens (Methanocella, Methanoregula), reinforcing the likely importance of aceticlastic methanogenesis to the overall production of methane. ΔGs for acetogenesis from H 2 to CO 2 approximated to -20 kJ mol -1 when acetate concentrations were low, indicating that acetogens may have contributed to the flow of carbon and reductant towards methane.
UR - http://www.scopus.com/inward/record.url?scp=84954453031&partnerID=8YFLogxK
U2 - 10.1038/ismej.2015.256
DO - 10.1038/ismej.2015.256
M3 - Article
VL - 10
SP - 1954
EP - 1966
JO - ISME J
JF - ISME J
SN - 1751-7362
IS - 8
ER -