Details
| Original language | English |
|---|---|
| Pages (from-to) | 45-50 |
| Number of pages | 6 |
| Journal | Geochemical Perspectives Letters |
| Volume | 29 |
| Publication status | Published - 9 Apr 2024 |
Abstract
The two step electron transfer during bacterial reduction of UVI to UIV is typically accompanied by mass-independent fractionation of the 238U and 235U isotopes, whereby the heavy isotope accumulates in the reduced product. However, the role of the UV intermediate in the fractionation mechanism is unresolved due to the challenges associated with its chemical stability. Here, we employed the UV stabilising ligand, dpaea2-, to trap aqueous UV during UVI reduction by Shewanella oneidensis. Whilst the first reduction step from UVI to UV displayed negligible fractionation, reduction of UV to UIV revealed mass-dependent isotope fractionation (preferential reduction of the 235U), contrary to most previous observations. This surprising behaviour highlights the control that the U-coordinating ligand exerts over the balance between reactant U supply, electron transfer rate, and UIV product sequestration, suggesting that UV speciation should be considered when using U isotope ratios to reconstruct environmental redox conditions.
ASJC Scopus subject areas
- Environmental Science(all)
- Environmental Chemistry
- Earth and Planetary Sciences(all)
- Geology
- Earth and Planetary Sciences(all)
- Geochemistry and Petrology
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In: Geochemical Perspectives Letters, Vol. 29, 09.04.2024, p. 45-50.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - The isotopic signature of UV during bacterial reduction
AU - Brown, A. R.
AU - Molinas, M.
AU - Roebbert, Y.
AU - Faizova, R.
AU - Vitova, T.
AU - Sato, A.
AU - Hada, M.
AU - Abe, M.
AU - Mazzanti, M.
AU - Weyer, S.
AU - Bernier-Latmani, R.
N1 - Funding Information: Funding for this work was provided by an ERC consolidator grant awarded to RB-L (725675: UNEARTH: \u201CUranium isotope fractionation: a novel biosignature to identify microbial metabolism on early Earth\u201D). This work was also supported by JSPS KAKENHI Grant Numbers JP19K22171, JP21H01864 and JP22J12551. A part of the calculations was performed at the Research Center for Computational Science, Okazaki, Japan (Project: 21-IMS-C049 and 22-IMS-C049).
PY - 2024/4/9
Y1 - 2024/4/9
N2 - The two step electron transfer during bacterial reduction of UVI to UIV is typically accompanied by mass-independent fractionation of the 238U and 235U isotopes, whereby the heavy isotope accumulates in the reduced product. However, the role of the UV intermediate in the fractionation mechanism is unresolved due to the challenges associated with its chemical stability. Here, we employed the UV stabilising ligand, dpaea2-, to trap aqueous UV during UVI reduction by Shewanella oneidensis. Whilst the first reduction step from UVI to UV displayed negligible fractionation, reduction of UV to UIV revealed mass-dependent isotope fractionation (preferential reduction of the 235U), contrary to most previous observations. This surprising behaviour highlights the control that the U-coordinating ligand exerts over the balance between reactant U supply, electron transfer rate, and UIV product sequestration, suggesting that UV speciation should be considered when using U isotope ratios to reconstruct environmental redox conditions.
AB - The two step electron transfer during bacterial reduction of UVI to UIV is typically accompanied by mass-independent fractionation of the 238U and 235U isotopes, whereby the heavy isotope accumulates in the reduced product. However, the role of the UV intermediate in the fractionation mechanism is unresolved due to the challenges associated with its chemical stability. Here, we employed the UV stabilising ligand, dpaea2-, to trap aqueous UV during UVI reduction by Shewanella oneidensis. Whilst the first reduction step from UVI to UV displayed negligible fractionation, reduction of UV to UIV revealed mass-dependent isotope fractionation (preferential reduction of the 235U), contrary to most previous observations. This surprising behaviour highlights the control that the U-coordinating ligand exerts over the balance between reactant U supply, electron transfer rate, and UIV product sequestration, suggesting that UV speciation should be considered when using U isotope ratios to reconstruct environmental redox conditions.
UR - http://www.scopus.com/inward/record.url?scp=85190948181&partnerID=8YFLogxK
U2 - 10.7185/geochemlet.2411
DO - 10.7185/geochemlet.2411
M3 - Article
AN - SCOPUS:85190948181
VL - 29
SP - 45
EP - 50
JO - Geochemical Perspectives Letters
JF - Geochemical Perspectives Letters
SN - 2410-339X
ER -