Diana Simionato

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Algae are interesting potential sources of biodiesel, although research is still needed to develop efficient large scale productions. One major factor affecting productivity is light use efficiency. The effect of different light regimes on the seawater alga Nannochloropsis gaditana was accessed monitoring growth rate and photosynthetic performances. N.(More)
Nannochloropsis gaditana belongs to Eustigmatophyceae, a class of eukaryotic algae resulting from a secondary endosymbiotic event. Species of this class have been poorly characterized thus far but are now raising increasing interest in the scientific community because of their possible application in biofuel production. Nannochloropsis species have a(More)
Biofuels from algae are highly interesting as renewable energy sources to replace, at least partially, fossil fuels, but great research efforts are still needed to optimize growth parameters to develop competitive large-scale cultivation systems. One factor with a seminal influence on productivity is light availability. Light energy fully supports algal(More)
Photosystem I (PSI) is a pigment protein complex catalyzing the light-driven electron transport from plastocyanin to ferredoxin in oxygenic photosynthetic organisms. Several PSI subunits are highly conserved in cyanobacteria, algae and plants, whereas others are distributed differentially in the various organisms. Here we characterized the structural and(More)
A major challenge for next decades is development of competitive renewable energy sources, highly needed to compensate fossil fuels reserves and reduce greenhouse gas emissions. Among different possibilities, which are currently under investigation, there is the exploitation of unicellular algae for production of biofuels and biodiesel in particular. Some(More)
Plants are often exposed to saturating light conditions, which can lead to oxidative stress. The carotenoid zeaxanthin, synthesized from violaxanthin by Violaxanthin De-Epoxidase (VDE) plays a major role in the protection from excess illumination. VDE activation is triggered by a pH reduction in the thylakoids lumen occurring under saturating light. In this(More)
Nannochloropsis is an eukaryotic alga of the phylum Heterokonta, originating from a secondary endosymbiotic event. In this work, we investigated how the photosynthetic apparatus responds to growth in different light regimes in Nannochloropsis gaditana. We found that intense illumination induces the decrease of both photosystem I and II contents and their(More)
When exposed to saturating light conditions photosynthetic eukaryotes activate the xanthophyll cycle where the carotenoid violaxanthin is converted into zeaxanthin by the enzyme violaxanthin de-epoxidase (VDE). VDE protein sequence includes 13 cysteine residues, 12 of which are strongly conserved in both land plants and algae. Site directed mutagenesis of(More)
Photosynthetic thylakoid membranes contain the protein machinery to convert sunlight in chemical energy and regulate this process in changing environmental conditions via interplay between lipid, protein and xanthophyll molecular constituents. This work addresses the molecular effects of zeaxanthin accumulation in thylakoids, which occurs in native systems(More)
Chlorella protothecoides is a valuable source of lipids that may be used for biodiesel production. The present work shows analysis of the potential of photoheterotrophic cultivation of C. protothecoides under various light intensities aiming to identify the conditions with maximal biomass and lipid content. An increase in light intensity was associated with(More)