A5100695316- Photosynthetic Processes and Mechanisms
- Algal biology and biofuel production
- Photoreceptor and optogenetics research
- Marine and coastal ecosystems
- Light effects on plants
- Lipid metabolism and biosynthesis
- Mitochondrial Function and Pathology
- Spectroscopy and Quantum Chemical Studies
- Plant Stress Responses and Tolerance
- Metalloenzymes and iron-sulfur proteins
- Plant Water Relations and Carbon Dynamics
- Biocrusts and Microbial Ecology
- Plant responses to elevated CO2
- Microbial Metabolic Engineering and Bioproduction
- Enzyme Catalysis and Immobilization
- Biodiesel Production and Applications
- Aquatic Ecosystems and Phytoplankton Dynamics
- Microbial Fuel Cells and Bioremediation
- Microbial Community Ecology and Physiology
- Hemoglobin structure and function
- Genomics and Phylogenetic Studies
- Arsenic contamination and mitigation
- ATP Synthase and ATPases Research
- Protist diversity and phylogeny
- Plant nutrient uptake and metabolism
CEA Cadarache
2015-2024
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2015-2024
Institut de Biosciences et Biotechnologies
2015-2024
Centre National de la Recherche Scientifique
2015-2024
Aix-Marseille Université
2014-2024
Institut de Biosciences et biotechnologies d'Aix-Marseille
2003-2019
Département Santé des Plantes et Environnement
2003-2019
Institute of Environmental Biology and Biotechnology
2007-2018
Ecologie Microbienne Lyon
2011-2016
Institut de Recherches en Technologies et Sciences pour le Vivant
1993-2008
When cultivated under stress conditions, many microalgae species accumulate both starch and oil (triacylglycerols). The model green microalga Chlamydomonas reinhardtii has recently emerged as a to test genetic engineering or cultivation strategies aiming at increasing lipid yields for biodiesel production. Blocking synthesis been suggested way boost accumulation. Here, we characterize the triacylglycerol (TAG) accumulation process in quantify TAGs various wild-type starchless strains.In...
Algal enzyme driven by blue light Microalgae make hydrocarbons. In searching for the responsible, Sorigué et al. found a glucose-methanolcholine oxidoreductase (see Perspective Scrutton). Expression of in Escherichia coli showed that hydrocarbon production requires visible light. fact, constant input photons to carry out its catalytic reaction. A long hydrophobic tunnel stabilizes fatty acid substrates proximity flavin adenine dinucleotide cofactor. Science , this issue p. 903 ; see also 872
The unicellular green alga Chlamydomonas reinhardtii is a prime model for deciphering processes occurring in the intracellular compartments of photosynthetic cell. Organelle-specific proteomic studies have started to delineate its various subproteomes, but sequence-based prediction software necessary assign proteins subcellular localizations at whole genome scale. Unfortunately, existing tools are oriented toward land plants and tend mispredict localization nuclear-encoded algal proteins,...
Microalgae are regarded as promising organisms to develop innovative concepts based on their photosynthetic capacity that offers more sustainable production than heterotrophic hosts. However, realize potential green cell factories, a major challenge is make microalgae easier engineer. A approach for rapid and predictable genetic manipulation use standardized synthetic biology tools workflows. To this end we have developed Modular Cloning toolkit the microalga Chlamydomonas reinhardtii. It...
Light makes light work of fatty acids Photosynthetic organisms are notable for their ability to capture energy and use it power biosynthesis. Some algae have gone a step beyond photosynthesis can initiate enzymatic photodecarboxylation acids, producing long-chain hydrocarbons. To understand this transformation, Sorigué et al. brought bear an array structural, computational, spectroscopic techniques fully characterized the catalytic cycle enzyme. These experiments consistent with mechanism...
The chloroplast NDH complex, NAD(P)H dehydrogenase, reduces the plastoquinone pool non-photochemically and is involved in cyclic electron flow around photosystem I (PSI). A transient increase chlorophyll fluorescence after turning off actinic light a result of activity. We focused on this subtle change to isolate nuclear mutants affected activity Arabidopsis by using imaging. crr2-1 crr2-2 (chlororespiratory reduction) are recessive mutant alleles which accumulation complex impaired. Except...
The ndh genes encoding for the subunits of NAD(P)H dehydrogenase complex represent largest family plastid without a clearly defined function. Tobacco (Nicotiana tabacum) transformants were produced in which thendhB gene was inactivated by replacing it with mutant version possessing translational stops coding region. Western-blot analysis indicated that no functional can be assembled transformants. Chlorophyll fluorescence measurements showed dark reduction plastoquinone pool stromal...
The interaction between hydrogen metabolism, respiration, and photosynthesis was studied in vivo whole cells of Synechocystis sp. strain PCC 6803 by continuously monitoring the changes gas concentrations (H2, CO2, O2) with an online mass spectrometer. activity bidirectional [NiFe]hydrogenase [H2:NAD(P) oxidoreductase], encoded hoxEFUYH genes, also measured independently proton-deuterium (H-D) exchange reaction presence D2. This technique allowed us to demonstrate that hydrogenase insensitive...
Abstract Oil bodies are sites of energy and carbon storage in many organisms including microalgae. As a step toward deciphering oil accumulation mechanisms algae, we used proteomics to analyze purified from the model microalga Chlamydomonas reinhardtii grown under nitrogen deprivation. Among 248 proteins (≥2 peptides) identified by LC‐MS/MS, 33 were putatively involved metabolism lipids (mostly acyl‐lipids sterols). Compared with recently reported body proteome, 19 new lipid identified,...
An inducible chloroplast gene expression system was developed in Chlamydomonas reinhardtii by taking advantage of the properties copper-sensitive cytochrome c(6) promoter and nucleus-encoded Nac2 protein. This protein is specifically required for stable accumulation psbD RNA acts on its 5' UTR. A construct containing coding sequence fused to introduced into nac2-26 mutant strain deficient Nac2. In this transformant, expressed copper-depleted but not copper-replete medium. Because encodes D2...
In photosynthetic eukaryotes, nonphotochemical plastoquinone (PQ) reduction is important for the regulation of electron flow. green microalgae where this process has been demonstrated, chloroplastic enzyme that catalyses PQ not identified yet. Here, we show by an RNA interference (RNAi) approach NDA2 gene, belonging to a type II NAD(P)H dehydrogenases family in microalga Chlamydomonas reinhardtii, encodes dehydrogenase functions reduce nonphotochemically alga. Using specific antibody, Nda2...
In higher plants, the Ndh complex reduces plastoquinones and is involved in cyclic electron flow around photosystem I, supplying extra-ATP for photosynthesis, particularly under environmental stress conditions. Based on plastid genome sequences, would contain 11 subunits (NDH-A to -K), but homologies with bacterial indicate probable existence of additional subunits. To identify missing subunits, tobacco (Nicotiana tabacum) NDH-H was His tagged at its N terminus using transformation. A...
Hydrogen photoproduction by eukaryotic microalgae results from a connection between the photosynthetic electron transport chain and plastidial hydrogenase. Algal H2 production is transitory phenomenon under most natural conditions, often viewed as safety valve protecting overreduction. From colony screening of an insertion mutant library unicellular green alga Chlamydomonas reinhardtii based on analysis dark-light chlorophyll fluorescence transients, we isolated impaired in cyclic flow...
In Chlamydomonas reinhardtii cells, H2 photoproduction can be induced in conditions of sulfur deprivation the presence acetate. The decrease photosystem II (PSII) activity by leads to anoxia, respiration becoming higher than photosynthesis, thereby allowing production. Two different electron transfer pathways, one PSII dependent and other independent, have been proposed account for photoproduction. this study, we investigated contribution both pathways as well acetate requirement production...
Abstract Under sulfur deprivation conditions, the green alga Chlamydomonas reinhardtii produces hydrogen in light a sustainable manner thanks to contribution of two pathways, direct and indirect. In pathway, photosystem II (PSII) supplies electrons hydrogenase through photosynthetic electron transport chain, while indirect is produced absence PSII I-dependent process. Starch metabolism has been proposed contribute both pathways by feeding respiration maintaining anoxia during pathway...