We used an ITS2 primary and secondary structure and Compensatory Base Changes (CBCs) analyses on new French and Spanish Dunallela salina strains to investigate their phylogenetic position and taxonomic status within the genus Dunaliella. Our analyses show a great diversity within D. salina (with only some clades not statistically supported) and reveal considerable genetic diversity and structur...

Microalgae have become an attractive natural source of a diverse range biomolecules, including enzymatic and non-enzymatic antioxidants; nevertheless, economically sustainable production such compounds from microalgae biomass is still challenging. The main hurdles are: (a) increasing yield; (b) achieving optimal cultivation conditions; (c) energy-efficient cost-effective downstream processing (...

A light-induced proton gradient (DeltapH) increase as exhibited by an increase of 9-aminoacridine fluorescence quenching is demonstrated between the external medium and the interior of the halophytic green alga Dunaliella salina. The formation and maintenance of the DeltapH is sensitive to electron transport inhibitors and to uncouplers. It is inhibited by p-chloromercuribenzenesulfonic acid (5...

Chemotactic properties of amino acids (L-alanine, glycine and L-lysine) and their oligopeptides (10(-6) M) and binding sites to these ligands were investigated in two unicellular models, the heterotrophic Tetrahymena pyriformis and the auxotrophic Dunaliella salina. Chemotaxis of Dunaliella induced by simple amino acids and their derivatives demonstrated that binding sites (receptors) for food ...

The plasma membrane H(+)-ATPase gene was cloned and sequenced from the extremely acidophilic green alga Dunaliella acidophila and from the extremely halotolerant Dunaliella salina. A special feature of the Dunaliella H(+)-ATPase is an extended C-terminal domain. The deduced amino acid sequences of the two proteins are 75% identical but differ in their C terminus. A hydrophilic loop within this ...

Since the interspecific competition represents a critical issue for biodiesel production in open mass cultures of microalgae, laboratory studies aimed to select competitive species receive significant interest. In this work, a laboratory approach based on the method of multisizing cell counting was developed to monitor the competition course of single algal species grown in mixed cultures. Two ...

Changes in phosphometabolites, following osmotic shock, were analyzed by two-dimensional thin layer chromatography, in extracts of the halotolerant alga DunalielIa salina in order to clarify the regulation of glycerol synthesis from starch. The experiments were carried out in wild-type and in osmotically defective mutant cells. It is demonstrated that hyperosmotic shock induces a decrease in fr...

In the present work we identified and quantified the effect of hydrodynamic stress on two different microalgae strains, Dunaliella tertiolecta and D. salina, cultivated in bench-scale bubble columns. The cell death rate constant increased with increasing gas-entrance velocity at the sparger. Dunaliella salina was slightly more sensitive than D. tertiolecta. The critical gas-entrance velocities ...

1. Dunaliella viridis Teodoresco thrives equally well in solutions of NaCl 1 to 4 mol and pH 6 to 9. 2. The organism is sensitive to calcium and magnesium, especially in acid medium. 3. Calcium and magnesium are antagonistic. In a molar solution of NaCl the antagonistic relation Mg:Ca is 4 to 5. In a 4 molar solution of NaCl the proportion becomes many times as great (20:1). 4. Although the str...