The transcriptional response of microbial communities in thawing Alaskan permafrost soils
Thawing of permafrost soils is expected to stimulate microbial decomposition and respiration of sequestered carbon. This could, in turn, increase atmospheric concentrations of greenhouse gasses, such as carbon dioxide and methane, and create a positive feedback to climate warming. Recent metagenomic...
| Main Authors: | , |
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| Format: | Journal Article |
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Frontiers Research Foundation
2015
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| Online Access: | http://hdl.handle.net/20.500.11937/32649 |
| _version_ | 1848753721426575360 |
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| author | Coolen, Marco Orsi, W. |
| author_facet | Coolen, Marco Orsi, W. |
| author_sort | Coolen, Marco |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | Thawing of permafrost soils is expected to stimulate microbial decomposition and respiration of sequestered carbon. This could, in turn, increase atmospheric concentrations of greenhouse gasses, such as carbon dioxide and methane, and create a positive feedback to climate warming. Recent metagenomic studies suggest that permafrost has a large metabolic potential for carbon processing, including pathways for fermentation and methanogenesis. Here, we performed a pilot study using ultrahigh throughput Illumina HiSeq sequencing of reverse transcribed messenger RNA to obtain a detailed overview of active metabolic pathways and responsible organisms in up to 70 cm deep permafrost soils at a moist acidic tundra location in Arctic Alaska. The transcriptional response of the permafrost microbial community was compared before and after 11 days of thaw. In general, the transcriptional profile under frozen conditions suggests a dominance of stress responses, survival strategies, and maintenance processes, whereas upon thaw a rapid enzymatic response to decomposing soil organic matter (SOM) was observed. Bacteroidetes, Firmicutes, ascomycete fungi, and methanogens were responsible for largest transcriptional response upon thaw. Transcripts indicative of heterotrophic methanogenic pathways utilizing acetate, methanol, and methylamine were found predominantly in the permafrost table after thaw. Furthermore, transcripts involved in acetogenesis were expressed exclusively after thaw suggesting that acetogenic bacteria are a potential source of acetate for acetoclastic methanogenesis in freshly thawed permafrost. Metatranscriptomics is shown here to be a useful approach for inferring the activity of permafrost microbes that has potential to improve our understanding of permafrost SOM bioavailability and biogeochemical mechanisms contributing to greenhouse gas emissions as a result of permafrost thaw. |
| first_indexed | 2025-11-14T08:29:01Z |
| format | Journal Article |
| id | curtin-20.500.11937-32649 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T08:29:01Z |
| publishDate | 2015 |
| publisher | Frontiers Research Foundation |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-326492017-09-13T15:26:24Z The transcriptional response of microbial communities in thawing Alaskan permafrost soils Coolen, Marco Orsi, W. Thawing of permafrost soils is expected to stimulate microbial decomposition and respiration of sequestered carbon. This could, in turn, increase atmospheric concentrations of greenhouse gasses, such as carbon dioxide and methane, and create a positive feedback to climate warming. Recent metagenomic studies suggest that permafrost has a large metabolic potential for carbon processing, including pathways for fermentation and methanogenesis. Here, we performed a pilot study using ultrahigh throughput Illumina HiSeq sequencing of reverse transcribed messenger RNA to obtain a detailed overview of active metabolic pathways and responsible organisms in up to 70 cm deep permafrost soils at a moist acidic tundra location in Arctic Alaska. The transcriptional response of the permafrost microbial community was compared before and after 11 days of thaw. In general, the transcriptional profile under frozen conditions suggests a dominance of stress responses, survival strategies, and maintenance processes, whereas upon thaw a rapid enzymatic response to decomposing soil organic matter (SOM) was observed. Bacteroidetes, Firmicutes, ascomycete fungi, and methanogens were responsible for largest transcriptional response upon thaw. Transcripts indicative of heterotrophic methanogenic pathways utilizing acetate, methanol, and methylamine were found predominantly in the permafrost table after thaw. Furthermore, transcripts involved in acetogenesis were expressed exclusively after thaw suggesting that acetogenic bacteria are a potential source of acetate for acetoclastic methanogenesis in freshly thawed permafrost. Metatranscriptomics is shown here to be a useful approach for inferring the activity of permafrost microbes that has potential to improve our understanding of permafrost SOM bioavailability and biogeochemical mechanisms contributing to greenhouse gas emissions as a result of permafrost thaw. 2015 Journal Article http://hdl.handle.net/20.500.11937/32649 10.3389/fmicb.2015.00197 Frontiers Research Foundation unknown |
| spellingShingle | Coolen, Marco Orsi, W. The transcriptional response of microbial communities in thawing Alaskan permafrost soils |
| title | The transcriptional response of microbial communities in thawing Alaskan permafrost soils |
| title_full | The transcriptional response of microbial communities in thawing Alaskan permafrost soils |
| title_fullStr | The transcriptional response of microbial communities in thawing Alaskan permafrost soils |
| title_full_unstemmed | The transcriptional response of microbial communities in thawing Alaskan permafrost soils |
| title_short | The transcriptional response of microbial communities in thawing Alaskan permafrost soils |
| title_sort | transcriptional response of microbial communities in thawing alaskan permafrost soils |
| url | http://hdl.handle.net/20.500.11937/32649 |