Turnover Rates of Intermediate Sulfur Species (Sx2-, S0, S2O32-, S4O62-, SO32-) in Anoxic Freshwater and Sediments
The microbial reduction of sulfate to sulfide coupled to organic matter oxidation followed by the transformation of sulfide back to sulfate drives a dynamic sulfur cycle in a variety of environments. The oxidative part of the sulfur cycle in particular is difficult to constrain because the eight ele...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2017-12-01
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| Series: | Frontiers in Microbiology |
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| Online Access: | http://journal.frontiersin.org/article/10.3389/fmicb.2017.02551/full |
| _version_ | 1818573239143628800 |
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| author | Alyssa J. Findlay Alexey Kamyshny |
| author_facet | Alyssa J. Findlay Alexey Kamyshny |
| author_sort | Alyssa J. Findlay |
| collection | DOAJ |
| description | The microbial reduction of sulfate to sulfide coupled to organic matter oxidation followed by the transformation of sulfide back to sulfate drives a dynamic sulfur cycle in a variety of environments. The oxidative part of the sulfur cycle in particular is difficult to constrain because the eight electron oxidation of sulfide to sulfate occurs stepwise via a suite of biological and chemical pathways and produces a wide variety of intermediates (Sx2-, S0, S2O32-, S4O62-, and SO32-), which may in turn be oxidized, reduced or disproportionated. Although the potential processes affecting these intermediates are well-known from microbial culture and geochemical studies, their significance and rates in the environment are not well constrained. In the study presented here, time-course concentration measurements of intermediate sulfur species were made in amended freshwater water column and sediment incubation experiments in order to constrain consumption rates and processes. In sediment incubations, consumption rates were Scolloidal0>Sx2->SO32-≈ S4O62-> S2O32-, which is consistent with previous measurements of SO32-, S4O62-, and S2O32- consumption rates in marine sediments. In water column incubations, however, the relative reactivity was Scolloidal0>SO32->Sx2-> S2O32-> S4O62-. Consumption of thiosulfate, tetrathionate and sulfite was primarily biological, whereas it was not possible to distinguish between abiotic and biological polysulfide consumption in either aqueous or sediment incubations. Scolloidal0 consumption in water column experiments was biologically mediated, however, rapid sedimentary consumption was likely due to reactions with iron minerals. These experiments provide important constraints on the biogeochemical reactivity of intermediate sulfur species and give further insight into the diversity of biological and geochemical processes that comprise (cryptic) environmental sulfur cycling. |
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| format | Article |
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| institution | Directory Open Access Journal |
| issn | 1664-302X |
| language | English |
| last_indexed | 2024-12-15T00:08:31Z |
| publishDate | 2017-12-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Microbiology |
| spelling | doaj.art-ad946fa1e60f48398982827cedb3a56f2022-12-21T22:42:39ZengFrontiers Media S.A.Frontiers in Microbiology1664-302X2017-12-01810.3389/fmicb.2017.02551292363Turnover Rates of Intermediate Sulfur Species (Sx2-, S0, S2O32-, S4O62-, SO32-) in Anoxic Freshwater and SedimentsAlyssa J. FindlayAlexey KamyshnyThe microbial reduction of sulfate to sulfide coupled to organic matter oxidation followed by the transformation of sulfide back to sulfate drives a dynamic sulfur cycle in a variety of environments. The oxidative part of the sulfur cycle in particular is difficult to constrain because the eight electron oxidation of sulfide to sulfate occurs stepwise via a suite of biological and chemical pathways and produces a wide variety of intermediates (Sx2-, S0, S2O32-, S4O62-, and SO32-), which may in turn be oxidized, reduced or disproportionated. Although the potential processes affecting these intermediates are well-known from microbial culture and geochemical studies, their significance and rates in the environment are not well constrained. In the study presented here, time-course concentration measurements of intermediate sulfur species were made in amended freshwater water column and sediment incubation experiments in order to constrain consumption rates and processes. In sediment incubations, consumption rates were Scolloidal0>Sx2->SO32-≈ S4O62-> S2O32-, which is consistent with previous measurements of SO32-, S4O62-, and S2O32- consumption rates in marine sediments. In water column incubations, however, the relative reactivity was Scolloidal0>SO32->Sx2-> S2O32-> S4O62-. Consumption of thiosulfate, tetrathionate and sulfite was primarily biological, whereas it was not possible to distinguish between abiotic and biological polysulfide consumption in either aqueous or sediment incubations. Scolloidal0 consumption in water column experiments was biologically mediated, however, rapid sedimentary consumption was likely due to reactions with iron minerals. These experiments provide important constraints on the biogeochemical reactivity of intermediate sulfur species and give further insight into the diversity of biological and geochemical processes that comprise (cryptic) environmental sulfur cycling.http://journal.frontiersin.org/article/10.3389/fmicb.2017.02551/fullsulfursulfide oxidationintermediate sulfur speciessulfur biogeochemistrythiosulfate |
| spellingShingle | Alyssa J. Findlay Alexey Kamyshny Turnover Rates of Intermediate Sulfur Species (Sx2-, S0, S2O32-, S4O62-, SO32-) in Anoxic Freshwater and Sediments Frontiers in Microbiology sulfur sulfide oxidation intermediate sulfur species sulfur biogeochemistry thiosulfate |
| title | Turnover Rates of Intermediate Sulfur Species (Sx2-, S0, S2O32-, S4O62-, SO32-) in Anoxic Freshwater and Sediments |
| title_full | Turnover Rates of Intermediate Sulfur Species (Sx2-, S0, S2O32-, S4O62-, SO32-) in Anoxic Freshwater and Sediments |
| title_fullStr | Turnover Rates of Intermediate Sulfur Species (Sx2-, S0, S2O32-, S4O62-, SO32-) in Anoxic Freshwater and Sediments |
| title_full_unstemmed | Turnover Rates of Intermediate Sulfur Species (Sx2-, S0, S2O32-, S4O62-, SO32-) in Anoxic Freshwater and Sediments |
| title_short | Turnover Rates of Intermediate Sulfur Species (Sx2-, S0, S2O32-, S4O62-, SO32-) in Anoxic Freshwater and Sediments |
| title_sort | turnover rates of intermediate sulfur species sx2 s0 s2o32 s4o62 so32 in anoxic freshwater and sediments |
| topic | sulfur sulfide oxidation intermediate sulfur species sulfur biogeochemistry thiosulfate |
| url | http://journal.frontiersin.org/article/10.3389/fmicb.2017.02551/full |
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