130 research outputs found
Production and characterization of two medium-chain-length polydroxyalkanoates by engineered strains of Yarrowia lipolytica
Background: The oleaginous yeast Yarrowia lipolytica is an organism of choice for the tailored production of various compounds such as biofuels or biopolymers. When properly engineered, it is capable of producing medium-chain-length polyhydroxyalkanoate (mcl-PHA), a biobased and biodegradable polymer that can be used as bioplastics or biopolymers for environmental and biomedical applications.Results: This study describes the bioproduction and the main properties of two different mcl-PHA polymers. We generated by metabolic engineering, strains of Y. lipolytica capable of accumulating more than 25% (g/g) of mcl-PHA polymers. Depending of the strain genetic background and the culture conditions, we produced (i) a mcl-PHA homopolymer of 3-hydroxydodecanoic acids, with a mass-average molar mass (M-w) of 316,000 g/mol, showing soft thermoplastic properties with potential applications in packaging and (ii) a mcl-PHA copolymer made of 3-hydroxyoctanoic (3HO), decanoic (3HD), dodecanoic (3HDD) and tetradecanoic (3TD) acids with a M-w of 128,000 g/mol, behaving like a thermoplastic elastomer with potential applications in biomedical material.Conclusion: The ability to engineer Y. lipolytica to produce tailored PHAs together with the range of possible applications regarding their biophysical and mechanical properties opens new perspectives in the field of PHA bioproduction
Production of medium chain fatty acid by Yarrowia lipolytica: Combining molecular design and TALEN to engineer the fatty acid synthase
Yarrowia lipolytica is a promising organism for the production of lipids of biotechnological interest and particularly for biofuel. In this study, we engineered lipid biosynthesis through rational engineering of the giant multifunctional Fatty Acid Synthase (FAS) enzyme to modulate fatty acid chain length and produce shorter fatty acids. Based on the hypothesis that the Ketoacyl Synthase (KS) domain, responsible for chain elongation in Yarrowia lipolytica, is directly involved in chain length specificity, a computer-based strategy was undertaken to re-design mutants of the Ketoacyl Synthase.
Molecular modelling of this domain in interaction with a C16-acyl substrate enabled identification of a key residue from the fatty acid binding site. This site was then targeted by mutagenesis in order to modify KS fatty acid chain length specificity. To introduce point mutations in this essential gene, we applied, for the first time, the TALEN technology to Yarrowia lipolytica and demonstrated the efficiency of the technique to perform site-directed mutagenesis at a specific genomic locus. Some mutants led to a significant increase of C14 fatty acid.
Thanks to the use of an elegant combination of genome editing technology and molecular modelling, this study provides for the first time, evidences that the KS domain of the fungal FASI system is directly involved in fatty acid chain length specificity
Antiviral Activities of Sulfated Polysaccharides Isolated from Sphaerococcus coronopifolius (Rhodophytha, Gigartinales) and Boergeseniella thuyoides (Rhodophyta, Ceramiales)
Water-soluble sulfated polysaccharides isolated from two red algae Sphaerococcus coronopifolius (Gigartinales, Sphaerococcaceae) and Boergeseniella thuyoides (Ceramiales, Rhodomelaceae) collected on the coast of Morocco inhibited in vitro replication of the Human Immunodeficiency Virus (HIV) at 12.5 ÎŒg/mL. In addition, polysaccharides were capable of inhibiting the in vitro replication of Herpes simplex virus type 1 (HSV-1) on Vero cells values of EC50 of 4.1 and 17.2 ÎŒg/mL, respectively. The adsorption step of HSV-1 to the host cell seems to be the specific target for polysaccharide action. While for HIV-1, these results suggest a direct inhibitory effect on HIV-1 replication by controlling the appearance of the new generations of virus and potential virucidal effect. The polysaccharides from S. coronopifolius (PSC) and B. thuyoides (PBT) were composed of galactose, 3,6-anhydrogalactose, uronics acids, sulfate in ratios of 33.1, 11.0, 7.7 and 24.0% (w/w) and 25.4, 16.0, 3.2, 7.6% (w/w), respectively
Réhabilitation du DPM: Bilan d'activité 2021. Secteur du TÚs
Le projet IDHEBARC sâintĂ©resse Ă lâimpact potentiel des travaux maritimes (nettoyage des friches ostrĂ©icoles, dragage des ports, âŠ) sur les herbiers de zostĂšres du Bassin dâArcachon. Ce projet pluriannuel comporte des actions de modĂ©lisation hydrosĂ©dimentaire visant Ă cartographier lâintensitĂ© des impacts potentiels, et un suivi de lâĂ©volution de lâemprise et du recouvrement des herbiers et de la composition de leur fond sĂ©dimentaire.
Ce rapport prĂ©sente les rĂ©sultats du suivi rĂ©alisĂ© dans le secteur du TĂšs (Bassin dâArcachon) oĂč des travaux de rĂ©habilitation du Domaine Public Maritime ont Ă©tĂ© rĂ©alisĂ©s entre fĂ©vrier 2022 et mai 2022
RĂ©habilitation du Domaine Public Maritime du Bassin dâArcachon â Secteur de Bourrut : Bilan dâactivitĂ© 2019
Le projet IDHEBARC sâintĂ©resse Ă lâimpact potentiel des travaux maritimes (nettoyage des friches ostrĂ©icoles, dragage des ports, âŠ) sur les herbiers de zostĂšres du Bassin dâArcachon. Ce rapport traite des premiers rĂ©sultats du suivi rĂ©alisĂ© dans le secteur de Bourrut oĂč des travaux de rĂ©habilitation du Domaine Public Maritime ont Ă©tĂ© initiĂ©s dĂ©but 2020
IDHEBARC 2022 : Bilan d'activité. Secteur de La Teste de Buch
Le projet IDHEBARC sâintĂ©resse Ă lâimpact potentiel des travaux maritimes (nettoyage des friches ostrĂ©icoles, dragage des ports, âŠ) sur les herbiers de zostĂšres du Bassin dâArcachon. Ce projet pluriannuel comporte des actions de modĂ©lisation hydrosĂ©dimentaire visant Ă cartographier lâintensitĂ© des impacts potentiels, et un suivi de lâĂ©volution de lâemprise et du recouvrement des herbiers et de la composition de leur fond sĂ©dimentaire. Ce rapport prĂ©sente les premiers rĂ©sultats du suivi rĂ©alisĂ© dans le secteur de La Teste de Buch (Bassin dâArcachon) oĂč des travaux de dragage ont Ă©tĂ© rĂ©alisĂ©s dĂ©but 2021
RĂ©habilitation du DPM : Cartographie des herbiers Ă Zostera noltei avant travaux. Secteur des Moussetes
Le projet IDHEBARC sâintĂ©resse Ă lâimpact potentiel des travaux maritimes (nettoyage des friches ostrĂ©icoles, dragage des ports, âŠ) sur les herbiers de zostĂšres du Bassin dâArcachon. Ce projet pluriannuel comporte des actions de modĂ©lisation hydrosĂ©dimentaire visant Ă cartographier lâintensitĂ© des impacts potentiels, et un suivi de lâĂ©volution de lâemprise et du recouvrement des herbiers et de la composition de leur fond sĂ©dimentaire.
Ce rapport présente les résultats de la cartographie des herbiers du secteur des Moussettes avant les travaux de réhabilitation du DPM
Chimie DCE dans les eaux littorales du bassin Adour-Garonne â Substances Hydrophobes. Mise Ă jour de lâindicateur chimie - DonnĂ©es 2018-2020
Ce rapport rend compte des derniers rĂ©sultats biotes validĂ©es (2018-2020) dans le cadre du suivi des contaminants chimique dans les masses dâeau littorales du bassin Adour Garonne. Une actualisation de lâindicateur chimie par lieu de surveillance est prĂ©sentĂ©e , cette prĂ©-Ă©valuation suit les consignes du REEEL 2018 et prend en compte les nouveaux seuils OSPAR et les Valeurs Guides Environnementales (VGE) rĂ©cemment rĂ©visĂ©e
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