Antimony Isotope Fractionation during Kinetic Sb(III) Oxidation by Antimony-Oxidizing Bacteria Pseudomonas sp. J1

authored by: Xiaocen Jia, Andreas Kaufmann, Marina Lazarov, Bing Wen, Stefan Weyer, Jianwei Zhou, Liyuan Ma, Juraj Majzlan
Abstract: Antimony (Sb) isotopic fractionation is frequently used as a proxy for biogeochemical processes in nature. However, to date, little is known about Sb isotope fractionation in biologically driven reactions. In this study, Pseudomonas sp. J1 was selected for Sb isotope fractionation experiments with varying initial Sb concentration gradients (50-200 μM) at pH 7.2 and 30 °C. Compared to the initial Sb(III) reservoir (δ¹²³Sb = 0.03 ± 0.01 ∼ 0.06 ± 0.01‰), lighter isotopes were preferentially oxidized to Sb(V). Relatively constant isotope enrichment factors (ϵ) of −0.62 ± 0.06 and −0.58 ± 0.02‰ were observed for the initial Sb concentrations ranging between 50 and 200 μM during the first 22 days. Therefore, the Sb concentration has a limited influence on Sb isotope fractionation during Sb(III) oxidation that can be described by a kinetically dominated Rayleigh fractionation model. Due to the decrease in the Sb-oxidation rate by Pseudomonas sp. J1, observed for the initial Sb concentration of 200 μM, Sb isotope fractionation shifted toward isotopic equilibrium after 22 days, with slightly heavy Sb(V) after 68 days. These findings provide the prospect of using Sb isotopes as an environmental tracer in the Sb biogeochemical cycle.
Organisation(s): Mineralogy Section
Geochemistry
External Organisation(s): China University of Geosciences
Friedrich Schiller University Jena
Ministry of Ecology and Environment of the People's Republic of China (MEE)
Type: Article
Journal: Environmental Science and Technology
Volume: 58
Pages: 11411-11420
No. of pages: 10
ISSN: 0013-936X
Publication date: 02.07.2024
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: General Chemistry, Environmental Chemistry
Electronic version(s): https://doi.org/10.1021/acs.est.3c10271 (Access: Closed)

BibTeX

@article{da7ad297ecb84ed98b9db42c9bacc12e,
title = "Antimony Isotope Fractionation during Kinetic Sb(III) Oxidation by Antimony-Oxidizing Bacteria Pseudomonas sp. J1",
abstract = "Antimony (Sb) isotopic fractionation is frequently used as a proxy for biogeochemical processes in nature. However, to date, little is known about Sb isotope fractionation in biologically driven reactions. In this study, Pseudomonas sp. J1 was selected for Sb isotope fractionation experiments with varying initial Sb concentration gradients (50-200 μM) at pH 7.2 and 30 °C. Compared to the initial Sb(III) reservoir (δ123Sb = 0.03 ± 0.01 ∼ 0.06 ± 0.01‰), lighter isotopes were preferentially oxidized to Sb(V). Relatively constant isotope enrichment factors (ϵ) of −0.62 ± 0.06 and −0.58 ± 0.02‰ were observed for the initial Sb concentrations ranging between 50 and 200 μM during the first 22 days. Therefore, the Sb concentration has a limited influence on Sb isotope fractionation during Sb(III) oxidation that can be described by a kinetically dominated Rayleigh fractionation model. Due to the decrease in the Sb-oxidation rate by Pseudomonas sp. J1, observed for the initial Sb concentration of 200 μM, Sb isotope fractionation shifted toward isotopic equilibrium after 22 days, with slightly heavy Sb(V) after 68 days. These findings provide the prospect of using Sb isotopes as an environmental tracer in the Sb biogeochemical cycle.",
keywords = "antimony (Sb), isotope fractionation, kinetic-dominated, microbial oxidation, Sb(III)-oxidizing bacteria",
author = "Xiaocen Jia and Andreas Kaufmann and Marina Lazarov and Bing Wen and Stefan Weyer and Jianwei Zhou and Liyuan Ma and Juraj Majzlan",
note = "Publisher Copyright: {\textcopyright} 2024 American Chemical Society.",
year = "2024",
month = jul,
day = "2",
doi = "10.1021/acs.est.3c10271",
language = "English",
volume = "58",
pages = "11411--11420",
journal = "Environmental Science and Technology",
issn = "0013-936X",
publisher = "American Chemical Society",
number = "26",
}