The growth of the freshwater microalga Scenedesmus obliquus was studied at 30°C in a mineral culture medium with phosphorus concentrations of between 0 and 372 pro. The values for the specific growth rates, between So=0 #m and S,=298 pro, fitted a semistructured substrate-limitation model with #,,~ = 0.0466 h P.,,2 = 0.0256 h ~ and Ks = 0.2 ttm. The specific uptake rate of phosphorus reached a ...

RATIONALE Dietary sterol deficiencies can have severe life history consequences for consumers. Compound-specific stable isotope analysis (CSIA) was applied to the exploration of the sterol metabolic constraints and bioconversion capacities of the amphipod Gammarus roeselii. Evaluating structural sterol requirements has great potential to improve our understanding of the ecological relevance of ...

The effects of a commercially available anionic surfactant solution (FFD-6) on growth and morphology of a common green alga (Scenedesmus obliquus) and on survival and clearance rates of the water flea Daphnia magna were studied. The surfactant-solution elicited a morphological response (formation of colonies) in Scenedesmus at concentrations of 10-100 μl l(-1) that were far below the No Observe...

Freshwater salinization is a growing environmental issue caused by various anthropic or natural factors that lead to changes in water chemistry and physical conditions, affecting the survival diversity of phytoplankton. In this study, we tested physiological, morphological interspecific competition freshwater cyanobacterium Microcystis aeruginosa green algae Scenedesmus obliquus salinity stress...

Isothermal and non-isothermal torrefaction characteristics and kinetics of microalga Scenedesmus obliquus (S. obliquus) CNW-N are studied using thermogravimetric analysis. The pyrolysis of S. obliquus CNW-N with increasing temperature is characterized by four-stage decomposition. Depending on the torrefaction temperature, light, mild, and severe torrefaction from the weight loss and the maximum...

Hydrogen evolution is observed in the green alga Scenedesmus obliquus after a phase of anaerobic adaptation. In this study we report the biochemical and genetical characterization of a new type of Fe-hydrogenase (HydA) in this photosynthetic organism. The monomeric enzyme has a molecular mass of 44.5 kDa. The complete hydA cDNA of 2609 bp comprises an open reading frame encoding a polypeptide o...

Ribonucleoside diphosphate reductases isolated from Escherichia coli, baker's yeast, Ehrlich ascites tumor cells, and unicellular green alga (Scenedesmus obliquus) are inhibited strongly and uniformly by the polymeric triphenylmethane dye, aurintricarboxylic acid. The molecule appears to interact simultaneously with the enzyme's various nucleotide and catalytic (iron-organic radical) sites. Oli...

Growth intensity o f the green alga, Scenedesmus obliquus, was measured in autotrophic cultures, diluted once daily, between 20 and 30 °C in a light-dark cycle o f 16 : 8 h at initial optical densities between 0.02 and 1.2. Arrhenius analyses o f the results showed linear relationships be­ tween growth intensity and temperature below the temperature optimum. The temperature effects on growth, a...