Multiple sulfur isotope signatures of sulfite and thiosulfate reduction by the model dissimilatory sulfate-reducer, Desulfovibrio alaskensis str. G20
Dissimilatory sulfate reduction serves as a key metabolic carbon remineralization process in anoxic marine environments. Sulfate reducing microorganisms can impart a wide range in mass-dependent sulfur isotopic fractionation. As such, the presence and relative activity of these organisms is identifi...
| Main Authors: | , , , , , , |
|---|---|
| Other Authors: | |
| Format: | Article |
| Language: | en_US |
| Published: |
Frontiers Research Foundation
2014
|
| Online Access: | http://hdl.handle.net/1721.1/92501 https://orcid.org/0000-0002-1348-9584 |
| _version_ | 1826200511063261184 |
|---|---|
| author | Leavitt, William D. Cummins, Renata Schmidt, Marian L. Ono, Shuhei Bradley, Alexander S. Johnston, David T. Sim, Min Sub |
| author2 | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences |
| author_facet | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Leavitt, William D. Cummins, Renata Schmidt, Marian L. Ono, Shuhei Bradley, Alexander S. Johnston, David T. Sim, Min Sub |
| author_sort | Leavitt, William D. |
| collection | MIT |
| description | Dissimilatory sulfate reduction serves as a key metabolic carbon remineralization process in anoxic marine environments. Sulfate reducing microorganisms can impart a wide range in mass-dependent sulfur isotopic fractionation. As such, the presence and relative activity of these organisms is identifiable from geological materials. By extension, sulfur isotope records are used to infer the redox balance of marine sedimentary environments, and the oxidation state of Earth's oceans and atmosphere. However, recent work suggests that our understanding of microbial sulfate reduction (MSRs) may be missing complexity associated with the presence and role of key chemical intermediates in the reductive process. This study provides a test of proposed metabolic models of sulfate reduction by growing an axenic culture of the well-studied MSRs, Desulfovibrio alaskensis strain G20, under electron donor limited conditions on the terminal electron acceptors sulfate, sulfite or thiosulfate, and tracking the multiple S isotopic consequences of each condition set. The dissimilatory reduction of thiosulfate and sulfite produce unique minor isotope effects, as compared to the reduction of sulfate. Further, these experiments reveal a complex biochemistry associated with sulfite reduction. That is, under high sulfite concentrations, sulfur is shuttled to an intermediate pool of thiosulfate. Site-specific isotope fractionation (within thiosulfate) is very large (34ε ~ 30‰) while terminal product sulfide carries only a small fractionation from the initial sulfite (34ε < 10‰): a signature similar in magnitude to sulfate and thiosulfate reduction. Together these findings show that microbial sulfate reduction (MSR) is highly sensitive to the concentration of environmentally important sulfur-cycle intermediates (sulfite and thiosulfate), especially when thiosulfate and the large site-specific isotope effects are involved. |
| first_indexed | 2024-09-23T11:37:36Z |
| format | Article |
| id | mit-1721.1/92501 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T11:37:36Z |
| publishDate | 2014 |
| publisher | Frontiers Research Foundation |
| record_format | dspace |
| spelling | mit-1721.1/925012024-05-15T08:40:06Z Multiple sulfur isotope signatures of sulfite and thiosulfate reduction by the model dissimilatory sulfate-reducer, Desulfovibrio alaskensis str. G20 Leavitt, William D. Cummins, Renata Schmidt, Marian L. Ono, Shuhei Bradley, Alexander S. Johnston, David T. Sim, Min Sub Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Ono, Shuhei Sim, Min S. Dissimilatory sulfate reduction serves as a key metabolic carbon remineralization process in anoxic marine environments. Sulfate reducing microorganisms can impart a wide range in mass-dependent sulfur isotopic fractionation. As such, the presence and relative activity of these organisms is identifiable from geological materials. By extension, sulfur isotope records are used to infer the redox balance of marine sedimentary environments, and the oxidation state of Earth's oceans and atmosphere. However, recent work suggests that our understanding of microbial sulfate reduction (MSRs) may be missing complexity associated with the presence and role of key chemical intermediates in the reductive process. This study provides a test of proposed metabolic models of sulfate reduction by growing an axenic culture of the well-studied MSRs, Desulfovibrio alaskensis strain G20, under electron donor limited conditions on the terminal electron acceptors sulfate, sulfite or thiosulfate, and tracking the multiple S isotopic consequences of each condition set. The dissimilatory reduction of thiosulfate and sulfite produce unique minor isotope effects, as compared to the reduction of sulfate. Further, these experiments reveal a complex biochemistry associated with sulfite reduction. That is, under high sulfite concentrations, sulfur is shuttled to an intermediate pool of thiosulfate. Site-specific isotope fractionation (within thiosulfate) is very large (34ε ~ 30‰) while terminal product sulfide carries only a small fractionation from the initial sulfite (34ε < 10‰): a signature similar in magnitude to sulfate and thiosulfate reduction. Together these findings show that microbial sulfate reduction (MSR) is highly sensitive to the concentration of environmentally important sulfur-cycle intermediates (sulfite and thiosulfate), especially when thiosulfate and the large site-specific isotope effects are involved. United States. National Aeronautics and Space Administration (NASA-Exobiology) National Science Foundation (U.S.) (NSF GRFP Fellowship) National Science Foundation (U.S.) (NSF Career) National Science Foundation (U.S.) (NSF Instrument and facilities) National Science Foundation (U.S.) (NSF Low Temperature Geochemistry award) 2014-12-24T16:34:15Z 2014-12-24T16:34:15Z 2014-11 2014-09 Article http://purl.org/eprint/type/JournalArticle 1664-302X http://hdl.handle.net/1721.1/92501 Leavitt, William D., Renata Cummins, Marian L. Schmidt, Min S. Sim, Shuhei Ono, Alexander S. Bradley, and David T. Johnston. “Multiple Sulfur Isotope Signatures of Sulfite and Thiosulfate Reduction by the Model Dissimilatory Sulfate-Reducer, Desulfovibrio Alaskensis Str. G20.” Frontiers in Microbiology 5 (November 25, 2014). https://orcid.org/0000-0002-1348-9584 en_US http://dx.doi.org/10.3389/fmicb.2014.00591 Frontiers in Microbiology Creative Commons Attribution http://creativecommons.org/licenses/by/4.0/ application/pdf Frontiers Research Foundation Frontiers Research Foundation |
| spellingShingle | Leavitt, William D. Cummins, Renata Schmidt, Marian L. Ono, Shuhei Bradley, Alexander S. Johnston, David T. Sim, Min Sub Multiple sulfur isotope signatures of sulfite and thiosulfate reduction by the model dissimilatory sulfate-reducer, Desulfovibrio alaskensis str. G20 |
| title | Multiple sulfur isotope signatures of sulfite and thiosulfate reduction by the model dissimilatory sulfate-reducer, Desulfovibrio alaskensis str. G20 |
| title_full | Multiple sulfur isotope signatures of sulfite and thiosulfate reduction by the model dissimilatory sulfate-reducer, Desulfovibrio alaskensis str. G20 |
| title_fullStr | Multiple sulfur isotope signatures of sulfite and thiosulfate reduction by the model dissimilatory sulfate-reducer, Desulfovibrio alaskensis str. G20 |
| title_full_unstemmed | Multiple sulfur isotope signatures of sulfite and thiosulfate reduction by the model dissimilatory sulfate-reducer, Desulfovibrio alaskensis str. G20 |
| title_short | Multiple sulfur isotope signatures of sulfite and thiosulfate reduction by the model dissimilatory sulfate-reducer, Desulfovibrio alaskensis str. G20 |
| title_sort | multiple sulfur isotope signatures of sulfite and thiosulfate reduction by the model dissimilatory sulfate reducer desulfovibrio alaskensis str g20 |
| url | http://hdl.handle.net/1721.1/92501 https://orcid.org/0000-0002-1348-9584 |
| work_keys_str_mv | AT leavittwilliamd multiplesulfurisotopesignaturesofsulfiteandthiosulfatereductionbythemodeldissimilatorysulfatereducerdesulfovibrioalaskensisstrg20 AT cumminsrenata multiplesulfurisotopesignaturesofsulfiteandthiosulfatereductionbythemodeldissimilatorysulfatereducerdesulfovibrioalaskensisstrg20 AT schmidtmarianl multiplesulfurisotopesignaturesofsulfiteandthiosulfatereductionbythemodeldissimilatorysulfatereducerdesulfovibrioalaskensisstrg20 AT onoshuhei multiplesulfurisotopesignaturesofsulfiteandthiosulfatereductionbythemodeldissimilatorysulfatereducerdesulfovibrioalaskensisstrg20 AT bradleyalexanders multiplesulfurisotopesignaturesofsulfiteandthiosulfatereductionbythemodeldissimilatorysulfatereducerdesulfovibrioalaskensisstrg20 AT johnstondavidt multiplesulfurisotopesignaturesofsulfiteandthiosulfatereductionbythemodeldissimilatorysulfatereducerdesulfovibrioalaskensisstrg20 AT simminsub multiplesulfurisotopesignaturesofsulfiteandthiosulfatereductionbythemodeldissimilatorysulfatereducerdesulfovibrioalaskensisstrg20 |