Investigating the interaction of uranium(VI) with diatoms and their bacterial community: A microscopic and spectroscopic study

Autor: Yihua He, Sean Ting-Shyang Wei, Sindy Kluge, Katrin Flemming, Vladyslav Sushko, René Hübner, Robin Steudtner, Johannes Raff, Clarisse Mallet, Aude Beauger, Vincent Breton, Olivier Péron, Thorsten Stumpf, Susanne Sachs, Gilles Montavon
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: Ecotoxicology and Environmental Safety, Vol 284, Iss , Pp 116893- (2024)
Druh dokumentu: article
ISSN: 0147-6513
DOI: 10.1016/j.ecoenv.2024.116893
Popis: Diatoms and bacteria play a vital role in investigating the ecological effects of heavy metals in the environment. Despite separate studies on metal interactions with diatoms and bacteria, there is a significant gap in research regarding heavy metal interactions within a diatom-bacterium system, which closely mirrors natural conditions. In this study, we aim to address this gap by examining the interaction of uranium(VI) (U(VI)) with Achnanthidium saprophilum freshwater diatoms and their natural bacterial community, primarily consisting of four successfully isolated bacterial strains (Acidovorax facilis, Agrobacterium fabrum, Brevundimonas mediterranea, and Pseudomonas peli) from the diatom culture. Uranium (U) bio-association experiments were performed both on the xenic A. saprophilum culture and on the four bacterial isolates. Scanning electron microscopy and transmission electron microscopy coupled with spectrum imaging analysis based on energy-dispersive X-ray spectroscopy revealed a clear co-localization of U and phosphorus both on the surface and inside A. saprophilum diatoms and the associated bacterial cells. Time-resolved laser-induced fluorescence spectroscopy with parallel factor analysis identified similar U(VI) binding motifs both on A. saprophilum diatoms and the four bacterial isolates. This is the first work providing valuable microscopic and spectroscopic data on U localization and speciation within a diatom-bacterium system, demonstrating the contribution of the co-occurring bacteria to the overall interaction with U, a factor non-negligible for future modeling and assessment of radiological effects on living microorganisms.
Databáze: Directory of Open Access Journals
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