Role of Ester Sulfate and Organic Disulfide in Mercury Methylation in Peatland Soils.

Autor:	Pierce CE; Department of Soil, Water, and Climate, University of Minnesota, St. Paul, Minnesota 55108, United States., Furman OS; Department of Soil, Water, and Climate, University of Minnesota, St. Paul, Minnesota 55108, United States., Nicholas SL; Department of Soil, Water, and Climate, University of Minnesota, St. Paul, Minnesota 55108, United States., Wasik JC; Plant and Earth Science Department, University of Wisconsin River Falls, River Falls, Wisconsin 54022, United States., Gionfriddo CM; Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States., Wymore AM; Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States., Sebestyen SD; USDA Forest Service, Northern Research Station, Grand Rapids, Minnesota 55744, United States., Kolka RK; USDA Forest Service, Northern Research Station, Grand Rapids, Minnesota 55744, United States., Mitchell CPJ; Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, Scarborough, Ontario M1C 1A4, Canada., Griffiths NA; Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States., Elias DA; Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States., Nater EA; Department of Soil, Water, and Climate, University of Minnesota, St. Paul, Minnesota 55108, United States., Toner BM; Department of Soil, Water, and Climate, University of Minnesota, St. Paul, Minnesota 55108, United States.
Jazyk:	angličtina
Zdroj:	Environmental science & technology [Environ Sci Technol] 2022 Jan 18; Vol. 56 (2), pp. 1433-1444. Date of Electronic Publication: 2022 Jan 03.
DOI:	10.1021/acs.est.1c04662
Abstrakt:	We examined the composition and spatial correlation of sulfur and mercury pools in peatland soil profiles by measuring sulfur speciation by 1s X-ray absorption near-edge structure spectrocopy and mercury concentrations by cold vapor atomic fluorescence spectroscopy. Also investigated were the methylation/demethylation rate constants and the presence of hgc AB genes with depth. Methylmercury (MeHg) concentration and organic disulfide were spatially correlated and had a significant positive correlation ( p < 0.05). This finding is consistent with these species being products of dissimilatory sulfate reduction. Conversely, a significant negative correlation between organic monosulfides and MeHg was observed, which is consistent with a reduction in Hg(II) bioavailability via complexation reactions. Finally, a significant positive correlation between ester sulfate and instantaneous methylation rate constants was observed, which is consistent with ester sulfate being a substrate for mercury methylation via dissimilatory sulfate reduction. Our findings point to the importance of organic sulfur species in mercury methylation processes, as substrates and products, as well as potential inhibitors of Hg(II) bioavailability. For a peatland system with sub-μmol L -1 porewater concentrations of sulfate and hydrogen sulfide, our findings indicate that the solid-phase sulfur pools, which have a much larger sulfur concentration range, may be accessible to microbial activity or exchanging with the porewater.
Databáze:	MEDLINE
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