| Title | Metagenomic evidence for sulfur lithotrophy by epsilonproteobacteria as the major energy source for primary productivity in a sub-aeriel arctic glacial deposit, Borup Fiord Pass |
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| Author | Wright, K E; Williamson, C; Grasby, S E ; Spear, J R; Templeton, A S |
| Source | Frontiers in microbiology vol. 4, 63, 2013 p. 1-20, https://doi.org/10.3389/fmicb.2013.00063  Open Access |
| Year | 2013 |
| Alt Series | Earth Sciences Sector, Contribution Series 20120201 |
| Publisher | Frontiers Media SA |
| Document | serial |
| Lang. | English |
| Media | on-line; digital |
| File format | pdf |
| Province | Nunavut |
| NTS | 340B/10 |
| Area | Borup Fiord Pass; Ellesmere Island |
| Lat/Long WENS | -84.0000 -82.0000 80.7500 80.5000 |
| Subjects | surficial geology/geomorphology; sulphur; energy resources; energy; biogeology; arctic geology; Borup Fiord Pass Glacier |
| Illustrations | location maps; photographs; tables; histograms; charts |
| Program | GEM:
Geo-mapping for Energy and Minerals Sverdrup Sedimentary Basin |
| Released | 2013 01 01 |
| Abstract | We combined free energy calculations and metagenomic analyses of an elemental sulfur (S0) deposit on the surface of Borup Fiord Pass Glacier in the Canadian High Arctic to investigate whether the energy
available from different redox reactions in an environment predicts microbial metabolism. Many S, C, Fe, As, Mn, and NH4+ oxidation reactions were predicted to be energetically feasible in the deposit, and aerobic oxidation of S0 was the most
abundant chemical energy source. Small subunit ribosomal RNA (SSU rRNA) gene sequence data showed that the dominant phylotypes were Sulfurovum and Sulfuricurvum, both Epsilonproteobacteria known to be capable of sulfur lithotrophy. Sulfur redox genes
were abundant in the metagenome, but sox genes were significantly more abundant than reverse dsr (dissimilatory sulfite reductase) genes. Interestingly, there appeared to be habitable niches that were unoccupied at the depth of genome coverage
obtained. Photosynthesis and NH4+ oxidation should both be energetically favorable, but we found few or no functional genes for oxygenic or anoxygenic photosynthesis, or for NH4+ oxidation by either oxygen (nitrification) or nitrite (anammox). The
free energy, SSU rRNA gene and quantitative functional gene data are all consistent with the hypothesis that sulfur-based chemolithoautotrophy by Epsilonproteobacteria (Sulfurovum and Sulfuricurvum) is the main form of primary productivity at this
site, instead of photosynthesis. This is despite the presence of 24-h sunlight, and the fact that photosynthesis is not known to be inhibited by any of the environmental conditions present. This is the first time that Sulfurovum and Sulfuricurvum
have been shown to dominate a sub-aerial environment, rather than anoxic or sulfidic settings. We also found that Flavobacteria dominate the surface of the sulfur deposits. We hypothesize that this aerobic heterotroph uses enough oxygen to create a
microoxic environment in the sulfur below, where the Epsilonproteobacteria can flourish. |
| GEOSCAN ID | 291845 |
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