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| Amara, Anis; Quiniou, Francoise; Durand, Gael; El Bour, Monia; Boudabous, Abdellatif; Hourmant, Annick. |
| The triazole fungicide epoxiconazole is extensively used to control fungi on crops and may present some potential risk from runoff on coastal ecosystems located close to agricultural areas. Phytotoxicity assessments were conducted on the marine diatom Chaetoceros calcitrans using both the active ingredient and its formulated product (Opus). The 3-day EC50 using cell count was 2.31 mg/L for epoxiconazole active ingredient and 2.9 mu g/L for epoxiconazole-formulated. The fungicide produced an increase of cellular volume, pigment (chlorophylls a, c, and carotenoids) content, ATP synthesis, and rates of photosynthesis and respiration. Progressive algal cell recovery from epoxiconazole effects occurred after 3 days, with the increasing cell density. Differences... |
| Tipo: Text |
Palavras-chave: Age cell; Chaetoceros calcitrans; Culture conditions; Epoxiconazole; Growth; Physiological parameters. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00130/24105/22491.pdf |
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| Hourmant, Annick; Arzul, Genevieve. |
| Parmi les substances azotées de la matière organique dissoute, les polyamines semblent jouer un rôle particulier. Ces molécules sont des produits de décarboxylation de l'arginine et de l'ornithine, acides aminés basiques dont le dernier est le 2eme en abondance (après la leucine) dans les populations vieillissantes de la diatomée Chaetoceros gracile (Poulet et Martin-Jezequel, 1983). Les polyamines comprennent différentes molécules : la putrescine, la cadavérine, la spermine, la spermidine ... et résultent d'une façon générale, de toute dégradation de matière organique. Or ces molécules se rencontrent aussi dans les cellules algales en cours de division (Hourmant et al., 1994), principalement au début de la phaseS (Maiss et al., 1982) et avant... |
| Tipo: Text |
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| Ano: 1999 |
URL: http://archimer.ifremer.fr/doc/00105/21642/19223.pdf |
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| Hourmant, Annick; Amara, Anis; Pouline, Patrick; Durand, Gael; Arzul, Genevieve; Quiniou, Francoise. |
| The herbicide bentazon (CASRN 25057-89-0) is extensively used in agriculture in Brittany (France) to replace atrazine. Bentazon is not readily adsorbed by soil and therefore it enters adjacent freshwater ecosystems, making its way to estuarine and marine waters areas. Information regarding its effects on marine ecosystems is scarce. Phytotoxicity assessments were conducted in the laboratory on the common diatom Chaetoceros gracilis using both the active ingredient and its formulated product (Basamais). The 3 day EC50 Using cell counts were, respectively, 150 mg/L and 60 mu g/L for bentazon active ingredient and for bentazon-formulated while cellular volume was increased. Although bentazon is known as a photosystem II inhibitor, it produced an increase of... |
| Tipo: Text |
Palavras-chave: Photosynthesis; Marine diatom; Growth; Chlorophylls; Chaetoceros gracilis; Carotenoids; Bentazon; ATP. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6637.pdf |
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