Dissolved organic matter modulates the impact of herbicides on a freshwater alga: a laboratory study of a three-way interaction

Type Article
Date 2021-08
Language English
Author(s) Morin Soizic1, Coquillé Nathalie1, 2, 3, 4, Éon Mélissa1, Budzinski Hélène3, 4, Parlanti Édith3, 4, Stachowski-Haberkorn SabineORCID2
Affiliation(s) 1 : INRAE, UR EABX, 50 avenue de Verdun, F-33612 Cestas cedex, France
2 : Ifremer, BE, F-44000 Nantes, France
3 : Univ. Bordeaux, UMR 5805, CNRS, EPOC, LPTC, 351 Cours de la Libération, F-33405 Talence Cedex, France
4 : CNRS, UMR 5805, EPOC, LPTC, 351 Cours de la Libération, F-33405 Talence Cedex, France
5 : Ifremer, BRM, F‐44000 Nantes, France
Source Science Of The Total Environment (0048-9697) (Elsevier BV), 2021-08 , Vol. 782 , P. 146881 (10p.)
DOI 10.1016/j.scitotenv.2021.146881
WOS© Times Cited 1
Keyword(s) Chlorophyte, Ecotoxicity, DCPMU, Metolachlor-ESA, Degradation
Abstract

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.

Full Text
File Pages Size Access
Author's final draft 35 963 KB Open access
10 665 KB Access on demand
690 KB Access on demand
Top of the page

How to cite 

Morin Soizic, Coquillé Nathalie, Éon Mélissa, Budzinski Hélène, Parlanti Édith, Stachowski-Haberkorn Sabine (2021). Dissolved organic matter modulates the impact of herbicides on a freshwater alga: a laboratory study of a three-way interaction. Science Of The Total Environment, 782, 146881 (10p.). Publisher's official version : https://doi.org/10.1016/j.scitotenv.2021.146881 , Open Access version : https://archimer.ifremer.fr/doc/00688/80048/