FN Archimer Export Format PT J TI Dissolved organic matter modulates the impact of herbicides on a freshwater alga: a laboratory study of a three-way interaction BT AF Morin, Soizic Coquillé, Nathalie Éon, Mélissa Budzinski, Hélène Parlanti, Édith Stachowski-Haberkorn, Sabine AS 1:1;2:1,2,3,4;3:1;4:3,4;5:3,4;6:2; FF 1:;2:PDG-RBE-BE-LEX;3:;4:;5:;6:PDG-RBE-BRM-LPBA; C1 INRAE, UR EABX, 50 avenue de Verdun, F-33612 Cestas cedex, France Ifremer, BE, F-44000 Nantes, France Univ. Bordeaux, UMR 5805, CNRS, EPOC, LPTC, 351 Cours de la Libération, F-33405 Talence Cedex, France CNRS, UMR 5805, EPOC, LPTC, 351 Cours de la Libération, F-33405 Talence Cedex, France Ifremer, BRM, F‐44000 Nantes, France C2 INRAE, FRANCE IFREMER, FRANCE UNIV BORDEAUX, FRANCE CNRS, FRANCE IFREMER, FRANCE SI NANTES SE PDG-RBE-BE-LEX PDG-RBE-BRM-LPBA IN WOS Ifremer UPR copubli-france copubli-p187 copubli-univ-france IF 10.754 TC 2 UR https://archimer.ifremer.fr/doc/00688/80048/83039.pdf LA English DT Article DE ;Chlorophyte;Ecotoxicity;DCPMU;Metolachlor-ESA;Degradation AB In freshwater environments, microorganisms such as microalgae are influenced by the concentrations of dissolved chemicals but can modify the fate of these substances by biosorption, accumulation and even metabolization. In this laboratory study, we assessed the growth and physiology of non-axenic cultures of the chlorophyte Sphaerellopsis sp. exposed to environmental concentrations of diuron, irgarol and S-metolachlor (0.5, 0.5 and 5 μg.L-1, respectively) singly and in mixture, in the presence or absence of natural dissolved organic matter (DOM). The growth, photosynthetic efficiency and relative intracellular lipid content of Sphaerellopsis sp., as were measured after 14 days of exposure, as were the concentrations of bacteria in the cultures. DOM absorbance and fluorescence, and concentrations of the herbicides and their metabolites in the culture medium were also recorded. The growth of Sphaerellopsis sp. was very low in the absence of DOM but dramatically enhanced in treatments where DOM was added. As a result, the toxicity of the herbicides observed in treatments without DOM was overcome in those where DOM was added. The chemical characteristics of DOM were modified by the microalgae, and the fate of the herbicides was affected by the interaction between microorganisms (both bacteria and algae) and the DOM. Herbicide concentrations decreased over time, with a simultaneous increase in some of their metabolites, suggesting a biological degradation in the presence of DOM. PY 2021 PD AUG SO Science Of The Total Environment SN 0048-9697 PU Elsevier BV VL 782 UT 000655625700009 DI 10.1016/j.scitotenv.2021.146881 ID 80048 ER EF