Sublethal effects of the insecticide fenitrothion on freshwater phytopiankton

1995 ◽  
Vol 73 (1) ◽  
pp. 45-53 ◽  
Author(s):  
Robert A. Kent ◽  
Pierre-Yves Caux
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Sublethal Effects ◽  
Scenedesmus Obliquus ◽  
Total Lipid Content ◽  
Chlorella Pyrenoidosa ◽  
Selenastrum Capricornutum ◽  
Total Lipids ◽  
Fatty Acid Profiles ◽  
Bioconcentration Factors ◽  
Ankistrodesmus Falcatus

The effects of the insecticide fenitrothion (O,O-dimethyl-O-(3-methyl-4-nitrophenyl)phosphorothioate) were investigated on the unicellular phytoplankton Ankistrodesmus falcatus, Chlamydomonas reinhardtii, Chlamydomonas segnis, Chlorella pyrenoidosa, Navicula sp., Scenedesmus obliquus, Selenastrum capricornutum, and Staurastrum sp. at concentrations of 0.1, 1.0, and 10 mg∙L−1. Following a 24-h exposure, total lipids, fatty acid profiles, and bioaccumulation of fenitrothion into algal cells were determined for the above species. Total lipids may play an important role in determining sensitivity of phytoplankton to fenitrothion stress over 96-h exposures. A saturation occurred in A. falcatus membranes represented by the 5.4 and 4.3% increases in palmitic (16:0) and oleic (18:1) acids, respectively, and 1.8 and 7.6% decreases in linoleic (18:2) and linolenic (18:3) acids, respectively. This resulted in a shift from a profile dominated by linolenic (18:3) acid to one dominated by the more saturated oleic (18:1) acid. Bioconcentration factors (BCF), or the ratio of the total radiocarbon associated with algae, calculated for viable Chlamydomonas reinhardtii and Chlamydomonas segnis cells were 293 and 124, respectively. BCFs for dead cells were 1261 and 1025 for the same species, respectively. These investigations showed differential insecticide bioaccumulation between species. This bioaccumulation was shown to be correlated with the total lipid content of algal cells. Key words: algae, fatty acids, fenitrothion, lipids, pesticide.

THE EFFECTS OF DIFFERENT DIETS ON THE FATTY ACID PROFILE OF THE FAIRY SHRIMP CHIROCEPHALUS RUFFOI COTTARELLI & MURA, 1984 (BRANCHIOPODA, ANOSTRACA)

Crustaceana ◽  
1999 ◽  
Vol 72 (6) ◽  
pp. 567-579 ◽  
Author(s):  
◽  
◽  
◽  
◽  
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Profile ◽  
Brine Shrimp ◽  
Total Lipid Content ◽  
Point Of View ◽  
Selenastrum Capricornutum ◽  
Standard Laboratory ◽  
Fatty Acid Profiles ◽  
Fairy Shrimps ◽  
Ad Libitum

AbstractNauplii of the anostracan Chirocephalus ruffoi were grown until sexual maturity under standard laboratory conditions (18 +/- 1 C; 12L/12D; 1600 lux light intensity) and fed ad libitum once a day on either an alga (Selenastrum capricornutum), baker's yeast, or a formulated diet. Both parents and cysts, as well as feeds were analysed for their fatty acid profiles and compared with wild adults and cysts. Significant differences (P < 0:05) were recorded among the different treatments. As far as total lipid content is concerned, a correlation was found between feeds and adult shrimps as well as between the latter and the cysts they produced during the different feeding tests. Significant differences (P < 0:05) were also recorded from a qualitative point of view. The results obtained provided evidence that the fatty acid profile of both fairy shrimps and cysts can be manipulated in order to improve their nutritional effectiveness, as it was previously shown in the case of the brine shrimp Artemia (Millamena et al., 1988; Lavens et al., 1989; Navarro & Amat, 1992) and of two other freshwater anostracan species (Mura et al., 1997a). Des nauplii de l'anostrace Chirocephalus ruffoi ont ete eleves jusqu'a maturite sexuelle dans des conditions standard de laboratoire (18 +/- 1 C, 12L/12D, 1600 lux d'intensite lumineuse) et nourris a volonte une fois par jour, soit avec une algue (Selenastrum capricornutum), soit avec de la levure de biere, soit avec une formule composee. Les adultes et les oeufs de duree, ainsi que les aliments, ont ete ensuite analyses quant a leur teneur et composition en acides gras et compares aux adultes et aux oeufs de duree sauvages. Des differences significatives (P < 0,05) ont ete notees suivant les differents traitements. En ce qui concerne le contenu total en lipides, une correlation a ete trouvee entre les aliments et les adultes ainsi qu'entre ces derniers et les oeufs de duree qu'ils produisent au cours des differents tests de nutrition. Des differences significatives (P < 0,05) ont ete observees d'un point de vue qualitatif. Les resultats obtenus mettent en evidence que le profil d'acides gras a la fois des anostraces et de leurs oeufs peut etre manipule dans le but d'ameliorer l'efficacite de la nutrition, comme il avait ete montre dans le cas d' Artemia (cf. Millamena et al., 1988; Lavens et al., 1989; Navarro & Amat, 1992) et de deux autres especes d'anostraces des eaux douces (Mura et al., 1997a).

Influence of mixing and shear stress on Chlorella vulgaris, Scenedesmus obliquus, and Chlamydomonas reinhardtii

2012 ◽  
Vol 25 (2) ◽  
pp. 485-495 ◽  
Author(s):  
Marco Leupold ◽  
Stefan Hindersin ◽  
Giselher Gust ◽  
Martin Kerner ◽  
Dieter Hanelt
Keyword(s):  
Shear Stress ◽  
Chlamydomonas Reinhardtii ◽  
Chlorella Vulgaris ◽  
Scenedesmus Obliquus

Inactivation and Reactivation of the Hydrogenases of the Green Algae Scenedesmus obliquus and Chlamydomonas reinhardtii

1993 ◽  
Vol 48 (1-2) ◽  
pp. 41-45 ◽  
Author(s):  
Thomas Urbig ◽  
Rüdiger Schulz ◽  
Horst Senger
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Green Algae ◽  
Scenedesmus Obliquus ◽  
Sodium Dithionite ◽  
Anaerobic Conditions ◽  
Whole Cells ◽  
Complete Inactivation

The hydrogenases of the green algae Scenedesmus obliquus and Chlamydomonas reinhardtii were activated under anaerobic conditions. Exposure of whole cells and cell-free homogenates to air lead to a complete inactivation of the hydrogenases. The inactivation in whole cells of Scenedesmus is faster than the inactivation of the cell-free homogenate. Inactivation of the hydrogenases could be reversed by anaerobic readaptation in whole cells. The inactivation of the hydrogenase in homogenates seems to be irreversible. Neither the removal of oxygen nor the addition of ATP, NAD(P)H, sodium dithionite, dithiothreitol, ferredoxin and thioredoxin to homogenates facilitated the reactivation of the hydrogenase. The occurrence of a hydrogenase regulating factor is discussed.

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