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dc.contributor.authorVazquez-Rodriguez, Adiari I.  Concept link
dc.contributor.authorHansel, Colleen M.  Concept link
dc.contributor.authorZhang, Tong  Concept link
dc.contributor.authorLamborg, Carl H.  Concept link
dc.contributor.authorSantelli, Cara M.  Concept link
dc.contributor.authorWebb, Samuel M.  Concept link
dc.contributor.authorBrooks, Scott C.  Concept link
dc.identifier.citationFrontiers in Microbiology 6 (2015): 596en_US
dc.description© The Author(s), 2015. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Frontiers in Microbiology 6 (2015): 596, doi:10.3389/fmicb.2015.00596.en_US
dc.description.abstractMercury (Hg) is a toxic heavy metal that poses significant environmental and human health risks. Soils and sediments, where Hg can exist as the Hg sulfide mineral metacinnabar (β-HgS), represent major Hg reservoirs in aquatic environments. Metacinnabar has historically been considered a sink for Hg in all but severely acidic environments, and thus disregarded as a potential source of Hg back to aqueous or gaseous pools. Here, we conducted a combination of field and laboratory incubations to identify the potential for metacinnabar as a source of dissolved Hg within near neutral pH environments and the underpinning (a)biotic mechanisms at play. We show that the abundant and widespread sulfur-oxidizing bacteria of the genus Thiobacillus extensively colonized metacinnabar chips incubated within aerobic, near neutral pH creek sediments. Laboratory incubations of axenic Thiobacillus thioparus cultures led to the release of metacinnabar-hosted Hg(II) and subsequent volatilization to Hg(0). This dissolution and volatilization was greatly enhanced in the presence of thiosulfate, which served a dual role by enhancing HgS dissolution through Hg complexation and providing an additional metabolic substrate for Thiobacillus. These findings reveal a new coupled abiotic-biotic pathway for the transformation of metacinnabar-bound Hg(II) to Hg(0), while expanding the sulfide substrates available for neutrophilic chemosynthetic bacteria to Hg-laden sulfides. They also point to mineral-hosted Hg as an underappreciated source of gaseous elemental Hg to the environment.en_US
dc.description.sponsorshipThis work was supported by the National Science Foundation Graduate Research Fellowship under Grant No. DGE-0644491 awarded to AV.en_US
dc.publisherFrontiers Mediaen_US
dc.rightsAttribution 4.0 International*
dc.subjectSulfur chemosynthesisen_US
dc.subjectMercury sulfide dissolutionen_US
dc.subjectSulfur metabolismen_US
dc.subjectSulfur oxidationen_US
dc.titleMicrobial- and thiosulfate-mediated dissolution of mercury sulfide minerals and transformation to gaseous mercuryen_US

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Attribution 4.0 International
Except where otherwise noted, this item's license is described as Attribution 4.0 International