Trace Metal Availability Affects Greenhouse Gas Emissions and Microbial Functional Group Abundance in Freshwater Wetland Sediments
| Autor: | Bongkeun Song, Rima B. Franklin, Georgios Giannopoulos, Bonnie L. Brown, Lars Elsgaard, Katherine R. Hartop |
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| Rok vydání: | 2020 |
| Předmět: |
Microbiology (medical)
0303 health sciences Denitrification denitrification wetland microbes 030306 microbiology Methanogenesis Chemistry carbon mineralization lcsh:QR1-502 trace metals Biogeochemistry Mineralization (soil science) Microbiology lcsh:Microbiology Microbial Physiology DNRA 03 medical and health sciences Microbial population biology Environmental chemistry Trace metal Microcosm 030304 developmental biology Original Research |
| Zdroj: | Frontiers in Microbiology Giannopoulos, G, Hartop, K R, Brown, B L, Song, B, Elsgaard, L & Franklin, R B 2020, ' Trace Metal Availability Affects Greenhouse Gas Emissions and Microbial Functional Group Abundance in Freshwater Wetland Sediments ', Frontiers in Microbiology, vol. 11, 560861 . https://doi.org/10.3389/fmicb.2020.560861 Frontiers in Microbiology, Vol 11 (2020) |
| ISSN: | 1664-302X |
| DOI: | 10.3389/fmicb.2020.560861 |
| Popis: | We investigated the effects of trace metal additions on microbial nitrogen (N) and carbon (C) cycling using freshwater wetland sediment microcosms amended with micromolar concentrations of copper (Cu), molybdenum (Mo), iron (Fe), and all combinations thereof. In addition to monitoring inorganic N transformations (NO3–, NO2–, N2O, NH4+) and carbon mineralization (CO2, CH4), we tracked changes in functional gene abundance associated with denitrification (nirS, nirK, nosZ), dissimilatory nitrate reduction to ammonium (DNRA; nrfA), and methanogenesis (mcrA). With regards to N cycling, greater availability of Cu led to more complete denitrification (i.e., less N2O accumulation) and a higher abundance of the nirK and nosZ genes, which encode for Cu-dependent reductases. In contrast, we found sparse biochemical evidence of DNRA activity and no consistent effect of the trace metal additions on nrfA gene abundance. With regards to C mineralization, CO2 production was unaffected, but the amendments stimulated net CH4 production and Mo additions led to increased mcrA gene abundance. These findings demonstrate that trace metal effects on sediment microbial physiology can impact community-level function. We observed direct and indirect effects on both N and C biogeochemistry that resulted in increased production of greenhouse gasses, which may have been mediated through the documented changes in microbial community composition and shifts in functional group abundance. Overall, this work supports a more nuanced consideration of metal effects on environmental microbial communities that recognizes the key role that metal limitation plays in microbial physiology. |
| Databáze: | OpenAIRE |
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