Selenium isotope ratios as indicators of selenium sources and oxyanion reduction

Johnson, Thomas M.; Herbel, Mitchell J.; Bullen, Thomas D.; Zawislanski, P.T.

doi:10.1016/s0016-7037(99)00279-3

Cited by 147 publications

(149 citation statements)

References 41 publications

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“…130 Te/ 125 Te ratios were then determined using the corrected data with a traditional "standard-sample-standard" bracketing technique. In runs using the Te "double spike" internal standard, isotope data were collected in 30 Te ratio was extracted from the isotope composition of the sample "double spike" mixture, using the same algorithm as that used previously in our work on selenium isotopes (17). The data are reported here as ␦ 130 Te, the per-mil difference between the resulting 130 Te/ 125 Te ratio of a sample and that of the starting material for each experiment.…”

Section: Methodsmentioning

confidence: 99%

“…Compared with what was found in the experiments conducted by Herbel et al (13) with selenium oxyanions, however, B. selenitireducens and S. barnesii achieved at least twice as great a fractionation during reduction of a lighter Se element (atomic weight ϭ 78.96) as they did during reduction of a heavier Te element (atomic weight ϭ 127.6). Nonetheless, the KIEs achieved by the two microbes used in this study open the possibility of employing stable Te isotope ratios to study the biogeochemistry of this element in nature, as has been attempted for selenium (17). Such an approach could help determine if natural enrichments of this element, such as those associated with marine ferromanganese deposits (11), are formed by reductive microbiological processes or by purely physical/chemical mechanisms.…”

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confidence: 98%

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Formation of Tellurium Nanocrystals during Anaerobic Growth of Bacteria That Use Te Oxyanions as Respiratory Electron Acceptors

Baesman

Bullen

Dewald

et al. 2007

Appl Environ Microbiol

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198

137

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Certain toxic elements support the metabolism of diverse prokaryotes by serving as respiratory electron acceptors for growth. Here, we demonstrate that two anaerobes previously shown to be capable of respiring oxyanions of selenium also achieve growth by reduction of either tellurate [Te ( , which cluster together, forming larger (ϳ1,000-nm) rosettes composed of numerous individual shards (ϳ100-nm width by 1,000-nm length). In contrast, Sulfurospirillum barnesii forms extremely small, irregularly shaped nanospheres (diameter < 50 nm) that coalesce into larger composite aggregates. Energy-dispersive X-ray spectroscopy and selected area electron diffraction indicate that both biominerals are composed entirely of Te and are crystalline, while Raman spectroscopy confirms that they are in the elemental state. These Te biominerals have specific spectral signatures (UV-visible light, Raman) that also provide clues to their internal structures. The use of microorganisms to generate Te nanomaterials may be an alternative for bench-scale syntheses. Additionally, they may also generate products with unique properties unattainable by conventional physical/chemical methods.

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Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 98%

Formation of Tellurium Nanocrystals during Anaerobic Growth of Bacteria That Use Te Oxyanions as Respiratory Electron Acceptors

Baesman

Bullen

Dewald

et al. 2007

Appl Environ Microbiol

Self Cite

198

137

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“…The "spike-subtracted" Fe isotope ratios were determined using an iterative technique after normalizing to 54 Fe/ 56 Fe [8]. Iron in all samples was separated from matrix elements in varying normalities of HNO 3 using either a single-column procedure with Eichrom's RE Spec ion exchange resin or a double-column procedure with Biorad's AG-50W-X8 cation exchange resin.…”

Section: Methodsmentioning

confidence: 99%

Iron isotopic fractionation during continental weathering

Fantle

DePaolo

2004

Earth and Planetary Science Letters

194

123

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“…For the abiotic processes, Se isotope fractionation occurs during chemical reduction of selenate to selenite but not during selenite adsorption onto ferric hydroxide and Se 0 oxidation (67). Abiotic reduction of Se(VI) to Se(IV) induced a fractionation of Ϫ5.5‰.…”

Section: Fractionation Of Selenium Isotopes By Selenium-respiring Bacmentioning

confidence: 98%

Ecology and Biotechnology of Selenium-Respiring Bacteria

Nancharaiah

2015

Microbiol Mol Biol Rev

361

232

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SUMMARY In nature, selenium is actively cycled between oxic and anoxic habitats, and this cycle plays an important role in carbon and nitrogen mineralization through bacterial anaerobic respiration. Selenium-respiring bacteria (SeRB) are found in geographically diverse, pristine or contaminated environments and play a pivotal role in the selenium cycle. Unlike its structural analogues oxygen and sulfur, the chalcogen selenium and its microbial cycling have received much less attention by the scientific community. This review focuses on microorganisms that use selenate and selenite as terminal electron acceptors, in parallel to the well-studied sulfate-reducing bacteria. It overviews the significant advancements made in recent years on the role of SeRB in the biological selenium cycle and their ecological role, phylogenetic characterization, and metabolism, as well as selenium biomineralization mechanisms and environmental biotechnological applications.

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Selenium isotope ratios as indicators of selenium sources and oxyanion reduction

Cited by 147 publications

References 41 publications

Formation of Tellurium Nanocrystals during Anaerobic Growth of Bacteria That Use Te Oxyanions as Respiratory Electron Acceptors

Formation of Tellurium Nanocrystals during Anaerobic Growth of Bacteria That Use Te Oxyanions as Respiratory Electron Acceptors

Iron isotopic fractionation during continental weathering

Ecology and Biotechnology of Selenium-Respiring Bacteria

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