Burkholderiaceae Are Key Acetate Assimilators During Complete Denitrification in Acidic Cryoturbated Peat Circles of the Arctic Tundra
Cryoturbated peat circles (pH 4) in the Eastern European Tundra harbor up to 2 mM pore water nitrate and emit the greenhouse gas N2O like heavily fertilized agricultural soils in temperate regions. The main process yielding N2O under oxygen limited conditions is denitrification, which is the sequent...
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ftdoajarticles:oai:doaj.org/article:7583a45c6bc04f16a963f7806b738b34 2023-05-15T15:14:09+02:00 Burkholderiaceae Are Key Acetate Assimilators During Complete Denitrification in Acidic Cryoturbated Peat Circles of the Arctic Tundra Stefanie A. Hetz Marcus A. Horn 2021-02-01T00:00:00Z https://doi.org/10.3389/fmicb.2021.628269 https://doaj.org/article/7583a45c6bc04f16a963f7806b738b34 EN eng Frontiers Media S.A. https://www.frontiersin.org/articles/10.3389/fmicb.2021.628269/full https://doaj.org/toc/1664-302X 1664-302X doi:10.3389/fmicb.2021.628269 https://doaj.org/article/7583a45c6bc04f16a963f7806b738b34 Frontiers in Microbiology, Vol 12 (2021) 16S rRNA stable isotope probing nitrous oxide climatechange permafrost affected soils isotope tracing Microbiology QR1-502 article 2021 ftdoajarticles https://doi.org/10.3389/fmicb.2021.628269 2022-12-31T07:04:53Z Cryoturbated peat circles (pH 4) in the Eastern European Tundra harbor up to 2 mM pore water nitrate and emit the greenhouse gas N2O like heavily fertilized agricultural soils in temperate regions. The main process yielding N2O under oxygen limited conditions is denitrification, which is the sequential reduction of nitrate/nitrite to N2O and/or N2. N2O reduction to N2 is impaired by pH < 6 in classical model denitrifiers and many environments. Key microbes of peat circles are important but largely unknown catalysts for C- and N-cycling associated N2O fluxes. Thus, we hypothesized that the peat circle community includes hitherto unknown taxa and is essentially unable to efficiently perform complete denitrification, i.e., reduce N2O, due to a low in situ pH. 16S rRNA analysis indicated a diverse active community primarily composed of the bacterial class-level taxa Alphaproteobacteria, Acidimicrobiia, Acidobacteria, Verrucomicrobiae, and Bacteroidia, as well as archaeal Nitrososphaeria. Euryarchaeota were not detected. 13C2- and 12C2-acetate supplemented anoxic microcosms with endogenous nitrate and acetylene at an in situ near pH of 4 were used to assess acetate dependent carbon flow, denitrification and N2O production. Initial nitrate and acetate were consumed within 6 and 11 days, respectively, and primarily converted to CO2 and N2, suggesting complete acetate fueled denitrification at acidic pH. Stable isotope probing coupled to 16S rRNA analysis via Illumina MiSeq amplicon sequencing identified acetate consuming key players of the family Burkholderiaceae during complete denitrification correlating with Rhodanobacter spp. The archaeal community consisted primarily of ammonia-oxidizing Archaea of Nitrososphaeraceae, and was stable during the incubation. The collective data indicate that peat circles (i) host acid-tolerant denitrifiers capable of complete denitrification at pH 4–5.5, (ii) other parameters like carbon availability rather than pH are possible reasons for high N2O emissions in situ, and (iii) ... Article in Journal/Newspaper Arctic permafrost Tundra Directory of Open Access Journals: DOAJ Articles Arctic Frontiers in Microbiology 12 |
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English |
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16S rRNA stable isotope probing nitrous oxide climatechange permafrost affected soils isotope tracing Microbiology QR1-502 |
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16S rRNA stable isotope probing nitrous oxide climatechange permafrost affected soils isotope tracing Microbiology QR1-502 Stefanie A. Hetz Marcus A. Horn Burkholderiaceae Are Key Acetate Assimilators During Complete Denitrification in Acidic Cryoturbated Peat Circles of the Arctic Tundra |
topic_facet |
16S rRNA stable isotope probing nitrous oxide climatechange permafrost affected soils isotope tracing Microbiology QR1-502 |
description |
Cryoturbated peat circles (pH 4) in the Eastern European Tundra harbor up to 2 mM pore water nitrate and emit the greenhouse gas N2O like heavily fertilized agricultural soils in temperate regions. The main process yielding N2O under oxygen limited conditions is denitrification, which is the sequential reduction of nitrate/nitrite to N2O and/or N2. N2O reduction to N2 is impaired by pH < 6 in classical model denitrifiers and many environments. Key microbes of peat circles are important but largely unknown catalysts for C- and N-cycling associated N2O fluxes. Thus, we hypothesized that the peat circle community includes hitherto unknown taxa and is essentially unable to efficiently perform complete denitrification, i.e., reduce N2O, due to a low in situ pH. 16S rRNA analysis indicated a diverse active community primarily composed of the bacterial class-level taxa Alphaproteobacteria, Acidimicrobiia, Acidobacteria, Verrucomicrobiae, and Bacteroidia, as well as archaeal Nitrososphaeria. Euryarchaeota were not detected. 13C2- and 12C2-acetate supplemented anoxic microcosms with endogenous nitrate and acetylene at an in situ near pH of 4 were used to assess acetate dependent carbon flow, denitrification and N2O production. Initial nitrate and acetate were consumed within 6 and 11 days, respectively, and primarily converted to CO2 and N2, suggesting complete acetate fueled denitrification at acidic pH. Stable isotope probing coupled to 16S rRNA analysis via Illumina MiSeq amplicon sequencing identified acetate consuming key players of the family Burkholderiaceae during complete denitrification correlating with Rhodanobacter spp. The archaeal community consisted primarily of ammonia-oxidizing Archaea of Nitrososphaeraceae, and was stable during the incubation. The collective data indicate that peat circles (i) host acid-tolerant denitrifiers capable of complete denitrification at pH 4–5.5, (ii) other parameters like carbon availability rather than pH are possible reasons for high N2O emissions in situ, and (iii) ... |
format |
Article in Journal/Newspaper |
author |
Stefanie A. Hetz Marcus A. Horn |
author_facet |
Stefanie A. Hetz Marcus A. Horn |
author_sort |
Stefanie A. Hetz |
title |
Burkholderiaceae Are Key Acetate Assimilators During Complete Denitrification in Acidic Cryoturbated Peat Circles of the Arctic Tundra |
title_short |
Burkholderiaceae Are Key Acetate Assimilators During Complete Denitrification in Acidic Cryoturbated Peat Circles of the Arctic Tundra |
title_full |
Burkholderiaceae Are Key Acetate Assimilators During Complete Denitrification in Acidic Cryoturbated Peat Circles of the Arctic Tundra |
title_fullStr |
Burkholderiaceae Are Key Acetate Assimilators During Complete Denitrification in Acidic Cryoturbated Peat Circles of the Arctic Tundra |
title_full_unstemmed |
Burkholderiaceae Are Key Acetate Assimilators During Complete Denitrification in Acidic Cryoturbated Peat Circles of the Arctic Tundra |
title_sort |
burkholderiaceae are key acetate assimilators during complete denitrification in acidic cryoturbated peat circles of the arctic tundra |
publisher |
Frontiers Media S.A. |
publishDate |
2021 |
url |
https://doi.org/10.3389/fmicb.2021.628269 https://doaj.org/article/7583a45c6bc04f16a963f7806b738b34 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic permafrost Tundra |
genre_facet |
Arctic permafrost Tundra |
op_source |
Frontiers in Microbiology, Vol 12 (2021) |
op_relation |
https://www.frontiersin.org/articles/10.3389/fmicb.2021.628269/full https://doaj.org/toc/1664-302X 1664-302X doi:10.3389/fmicb.2021.628269 https://doaj.org/article/7583a45c6bc04f16a963f7806b738b34 |
op_doi |
https://doi.org/10.3389/fmicb.2021.628269 |
container_title |
Frontiers in Microbiology |
container_volume |
12 |
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1766344647068614656 |