Data/hora: 01/06/2024 10:12:52

Provedor de dados: | 5
País: | France
Título: | Influence de la matière organique dissoute naturelle et d’herbicides, seuls et combinés, sur des microalgues marines et d’eau douce
Autores: | Coquillé, Nathalie.
Data: | 2017-04-04
Ano: | 2017
Palavras-chave: | Microalgues; Matière organique dissoute naturelle; MOD; Herbicides; Transformations chimiques; Toxicité.; Microalgae; Natural dissolved organic matter; DOM; Herbicides; Chemical transformations; Toxicity.
Resumo: | Microalgae are at the basis of aquatic food webs and may be the indirect target of herbicides from agricultural and urban uses. They also interact with other compounds from their environment such as natural dissolved organic matter (DOM), which can itself interact with herbicides. This thesis aimed to study, in laboratory controlled conditions, the influence of natural DOM on herbicide toxicity to microalgae by using monospecific, non-axenic cultures. The experiments included: natural freshwater and marine DOM, three herbicides (irgarol, diuron and S-metolachlor) singly and in mixtures, two freshwater microalgae (Gomphonema gracile and Sphaerellopsis sp.) and two marine microalgae (Chaetoceros calcitrans and Tetraselmis suecica). Effects were evaluated on microalgae growth, photosynthetic efficiency and relative lipid content. At the same time, changes in chemical environment over the experiments were measured through DOM composition and properties, as well as the concentrations in herbicides and their metabolites. The results of this work, which consider for the first time natural DOM as a whole, interacting with microalgae, their associated bacteria and herbicides, demonstrate the key role played by DOM in (i) the growth stimulation of four microalgae (and in return the DOM changes induced by microalgae), (ii) the modulation of herbicide toxicity and suggest (iii) the ability of Sphaerellopsis sp. and/or its associated bacteria to biodegrade diuron in non-axenic conditions.
Tipo: | Text
Idioma: | Francês

Identificador:

https://archimer.ifremer.fr/doc/00461/57245/59250.pdf

https://archimer.ifremer.fr/doc/00461/57245/

Editor: | Université de Bordeaux
Formato: | application/pdf

Fonte:

2017 Université de Bordeaux

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