Publications associées à Laboratoire de microbiologie environnementale

Organic matters, but inorganic matters too: column examination of elevated mercury sorption on low organic matter aquifer material using concentrations and stable isotope ratios

Sorption of mercury (Hg) in soils is suggested to be predominantly associated with organic matter (OM). However, there is a growing collection of research that suggests that clay minerals and oxides are also important solid phases for the sorption of solu ...

2024

Diagenetic isotope exchange in biocalcites for paleoclimate reconstruction

Deyanira Graciela Cisneros Lazaro

The oxygen isotope compositions of fossil biocalcites, such as foraminifera, bivalves, brachiopods, and belemnites have allowed for reconstructions of sea surface and deep ocean temperatures throughout the Phanerozoic and constitute the most important reco ...

EPFL2024

Atomic level insight into irradiation effects in nuclear fuel materials

Shaileyee Bhattacharya

Microstructural evolution during in-pile irradiation, radiation damage effects and fission products behavior in UO2 nuclear fuel are key issues in understanding and for the modeling of the performance as well as safety characteristics of nuclear fuels in t ...

EPFL2024

The isotopic signature of U(V) during bacterial reduction

Marinella Mazzanti, Rizlan Bernier-Latmani, Margaux Camille Andréa Molinas, Radmila Faizova, Ashley Richards Brown

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 inte ...

2024

Metabolic Performance and Fate of Electrons during Nitrate-Reducing Fe(II) Oxidation by the Autotrophic Enrichment Culture KS Grown at Different Initial Fe/N Ratios

Natalia Jakus

Autotrophic nitrate-reducing Fe(II)-oxidizing (NRFeOx) microorganisms fix CO2 and oxidize Fe(II) coupled to denitrification, influencing carbon, iron, and nitrogen cycles in pH-neutral, anoxic environments. However, the distribution of electrons from Fe(II ...

AMER SOC MICROBIOLOGY2023

Implementing Multi-Electron Transfer Strategies in Uranium Chemistry

Dieuwertje Katelijn Modder

In the last decades, the activation of small molecules has attracted increasing attention for their use as cheap and abundant feedstock. Low-oxidation state uranium complexes have displayed high reactivity towards small molecules thanks to their unique pro ...

EPFL2023

Sulfurospirillum diekertiae sp. nov., a tetrachloroethene-respiring bacterium isolated from contaminated soil

Christof Holliger, Julien Maillard, Junxiong Wang

Two anaerobic, tetrachloroethene- (PCE-) respiring bacterial isolates, designated strain ACSDCE T and strain ACSTCE, were characterized using a polyphasic approach. Cells were Gram-stain-negative, motile, non-spore-forming and shared a vibrioid- to spirill ...

2023

A Route to Stabilize Uranium(II) and Uranium(I) Synthons in Multimetallic Complexes

Rosario Scopelliti, Marinella Mazzanti, Ivica Zivkovic, Dieuwertje Katelijn Modder

Herein, we report the redox reactivity of a multimetallic uranium complex supported by triphenylsiloxide (−OSiPh3) ligands, where we show that low valent synthons can be stabilized via an unprecedented mechanism involving intramolecular ligand migration. T ...

Wiley-VCH Verlag GmbH2023

Sulfur-cycling chemolithoautotrophic microbial community dominates a cold, anoxic, hypersaline Arctic spring

Ianina Altshuler

Background Gypsum Hill Spring, located in Nunavut in the Canadian High Arctic, is a rare example of a cold saline spring arising through thick permafrost. It perennially discharges cold (similar to 7 degrees C), hypersaline (7-8% salinity), anoxic (similar ...

BMC2023

Mercury Isotope Fractionation during Dark Abiotic Reduction of Hg(II) by Dissolved, Surface-Bound, and Structural Fe(II)

Lorenz Schwab

Stable mercury (Hg) isotope ratios are an emerging tracer for biogeochemical transformations in environmental systems, but their application requires knowledge of isotopic enrichment factors for individual processes. We investigated Hg isotope fractionatio ...

Amer Chemical Soc2023

Spatially Explicit Linkages Between Redox Potential Cycles and Soil Moisture Fluctuations

Andrea Rinaldo, Rizlan Bernier-Latmani, Paolo Benettin, Manon Frutschi, Simiao Wang, Filippo Miele, Mitra Asadollahi

Reduction-oxidation cycles measured through soil redox potential (Eh) are associated with dynamic soil microbial activity. Understanding changes in the composition of, and resource use by, soil microbial communities requires Eh predictability under shiftin ...

American Geophysical Union2023

Biostimulation as a sustainable solution for acid neutralization and uranium immobilization post acidic in-situ recovery

Rizlan Bernier-Latmani, Pierre Rossi, Thomas Coral

Major uranium (U) deposits worldwide are exploited by acid leaching, known as 'in-situ recovery' (ISR). ISR involves the injection of an acid fluid into ore-bearing aquifers and the pumping of the resulting metal-containing solution through cation exchange ...

2022

Active anaerobic methane oxidation and sulfur disproportionation in the deep terrestrial subsurface

Rizlan Bernier-Latmani, Manon Frutschi, Emma Bell, Chen Qian

Microbial life is widespread in the terrestrial subsurface and present down to several kilometers depth, but the energy sources that fuel metabolism in deep oligotrophic and anoxic environments remain unclear. In the deep crystalline bedrock of the Fennosc ...

2022

Multi-electron Transfer by U(II) and Masked U(II) Complexes

Marinella Mazzanti

Complexes of uranium in low oxidation state have shown the ability to activate non-reactive small molecules such as N-2. However, the multi-electron transfer required for such activation remains limited in uranium chemistry. Here, we review our recent rese ...

SWISS CHEMICAL SOC2022

Persistence of the isotopic signature of pentavalent uranium in magnetite

Rizlan Bernier-Latmani, Barbora Bártová, Zezhen Pan

Uranium isotopic signatures can be harnessed to monitor the reductive remediation of subsurface contamination or to reconstruct paleo-redox environments. However, the mechanistic underpinnings of the isotope fractionation associated with U reduction remain ...

2022

Growth and persistence of an aerobic microbial community in Wyoming bentonite MX-80 despite anoxic in-situ conditions

Rizlan Bernier-Latmani, Manon Frutschi, Niels Burzan, Roberta Murad Lima

Microbial activity has the potential to enhance the corrosion of high-level radioactive waste disposal canisters, which, in the proposed Swiss deep geological repository, will be embedded in bentonite and placed in the Opalinus Clay rock formation (OPA). T ...

Frontiers Media SA2022

Insights into the microbial reduction of pentavalent and hexavalent uranium species by Shewanella oneidensis MR-1

Margaux Camille Andréa Molinas

Decades of uranium-related activities such as ore mining, nuclear power generation, weapon manufacture, storage of nuclear wastes, have contributed to the release of U in the environment. U occurrence is concerning, since in surface environments, U is typi ...

EPFL2021

Design, synthesis, reactivity, and magnetic properties of uranium based oxide and nitride complexes

Luciano Barluzzi

The activation of small molecules is a paramount challenge in modern chemistry. The use of cheap and abundant molecules such as N2, H2, CO2, or CO as energy supplies or as precursors for fine chemicals production is highly desirable. In particular, the onl ...

EPFL2021

Systematic investigations of uranium carbide composites oxidation from micro- to nano-scale: Application to waste disposal

Nhât-Tân Vuong

The production of radioisotope beams at the ISOLDE (Isotope Separator OnLine DEvice) facility at CERN is achieved by irradiating target materials (e.g. uranium carbides and metal foils) with protons. The materials are usually operated at temperatures above ...

EPFL2021

Role of Iron Sulfide Phases in the Stability of Noncrystalline Tetravalent Uranium in Sediments

Rizlan Bernier-Latmani, Luca Loreggian

Uranium (U) in situ bioremediation has been investigated as a cost-effective strategy to tackle U contamination in the subsurface. While uraninite was believed to be the only product of bioreduction, numerous studies have revealed that noncrystalline U(IV) ...

AMER CHEMICAL SOC2020