WorldCat Identities

Grossi, Vincent

Overview
Works: 16 works in 22 publications in 2 languages and 24 library holdings
Roles: Opponent, Thesis advisor, Other, Author
Publication Timeline
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Most widely held works by Vincent Grossi
FORMATION ET DEVENIR DES PHYTADIENES DANS LE MILIEU MARIN : IMPLICATION DE CES HYDROCARBURES DANS LES PROCESSUS DE DEGRADATION DES CHLOROPHYLLES A CHAINE PHYTYLE by Vincent Grossi( Book )

2 editions published in 1996 in French and held by 3 WorldCat member libraries worldwide

LE BUT PRINCIPAL DE CETTE THESE A ETE DE DEMONTRER LE ROLE ET L'IMPORTANCE D'HYDROCARBURES (LES PHYTADIENES), AYANT POUR ORIGINE LA CHAINE PHYTYLE (PHYTOL) DES PRINCIPALES CHLOROPHYLLES, DANS LES PROCESSUS DE DEGRADATION DE CES PIGMENTS VEGETAUX. APRES LA MISE AU POINT D'UN PROTOCOLE EXPERIMENTAL ADAPTE A L'ANALYSE DE CES COMPOSES, CETTE ETUDE A APPORTE DES REPONSES CONCERNANT LA PRESENCE, LES MODES DE FORMATION ET LE DEVENIR DES PHYTADIENES DANS LA COLONNE D'EAU OCEANIQUE, AINSI QUE DANS LES COUCHES SEDIMENTAIRES. IL SEMBLE TOUT D'ABORD, QUE LES PHYTADIENES NE SOIENT PAS FORMES DANS LA COLONNE D'EAU, EN RAISON DE LEUR ABSENCE DANS DIFFERENTS TYPES D'ECHANTILLONS OBTENUS IN VITRO (CHAINES TROPHIQUES RECONSTITUEES EN MESOCOSMES OU CULTURES PHYTOPLANCTONIQUES), ET IN SITU (MATERIEL PARTICULAIRE). ILS LE SONT EN REVANCHE DANS LES SEDIMENTS SUPERFICIELS OU ILS CONSTITUENT DES INTERMEDIAIRES CLES DANS LA DIAGENESE PRECOCE DES CHLOROPHYLLES. LA NATURE DES ISOMERES DE PHYTADIENES FORMES PEUT ETRE RELIEE A LEUR MODE DE PRODUCTION BIOTIQUE OU ABIOTIQUE. LEUR DEVENIR EST, LUI, DEPENDANT DE LA PRESENCE D'OXYGENE: EN AEROBIOSE, LES PHYTADIENES SONT RAPIDEMENT DEGRADES PAR L'OXYGENE MOLECULAIRE (AUTO-OXYDATION) AVANT MEME QU'UNE BIODEGRADATION N'INTERVIENNE, ALORS QUE, DANS DES SEDIMENTS ANAEROBIES, LES PROCESSUS BACTERIENS SONT PREPONDERANTS ET SONT ACCOMPAGNES DE REACTIONS DE SULFURATION ABIOTIQUES. LES RELATIONS DIAGENETIQUES MISES EN EVIDENCE DANS CE TRAVAIL PERMETTENT D'EXPLIQUER LA FORMATION DE NOMBREUX COMPOSES ISOPRENOIDES REGULIEREMENT DETECTES DANS LES SEDIMENTS MARINS, ET METTENT EN EVIDENCE L'EXISTENCE DE STRUCTURES NOUVELLES, DONT CERTAINES SONT SUSCEPTIBLES D'ETRE RELIEES AUX CONDITIONS ENVIRONNEMENTALES
Fonctionnement biogéochimique du lac Masoko (Tanzanie), approche par les biomarqueurs lipidiques sédimentaires by Romain de Mesmay( Book )

3 editions published between 2008 and 2017 in French and held by 3 WorldCat member libraries worldwide

Lake Masoko (Rungwe Range, Tanzania) provides a continuous sedimentary record of environmental changes during the last 45,000 years. In this work, lipid biomarker content and their carbon isotopic composition (13C) from 10 selected sedimentary intervals allow paleoreconstruction of Lake Masoko since the last glacial period. Phytoplanktonic and bacterial biomarkers show high variability. Ten new structures of di- and mono-cyclic botryococcenes and partially reduced counterparts, triterpenoids specifically produced by Botrycoccus braunii B race, have been described for the first time in a 32 kyr BP interval. Their isotopic composition is highly enriched in 13C probably because of the use of bicarbonate as carbon source. Isotopic composition of n-alkanes shows that, in contrast with other records from tropical Africa, Lake Masoko surroundings are dominated by C3 land plants during the last 32,000 kyr BP. Lake Masoko could have been a refuge for biodiversity during glacial times. On the other hand, lipid biomarker content and their carbon isotopic composition from 18 sediment intervals covering the last 500 years offer a high resolution record for recent paleoenvironmental and anthropic changes. New very long chain C37 to C43 n-alkenes have been described for the first time in Lake Masoko sediments. Insects and other hypothetical producers of such alkenes have been discussed. Phytoplanktonic and bacterial biomarkers show rapid changes in lake ecosystem at decennial scale. Lacustrine productivity clearly increases during the last 500 years. Anthropic pressure on the ecosystem enhances lake productivity since 1940
Vers une meilleure compréhension des paléothermomètres moléculaires Uk'37 et TEX86 : apports d'une double approche données-modèles appliquée à la marge ibérique by Sophie Darfeuil( )

2 editions published in 2015 in French and held by 2 WorldCat member libraries worldwide

My PhD project aims at better understanding the functioning of both organic proxies of sea surface temperature (SST), Uk'37 and TEX86, especially in terms of season and depth of alkenone and tetraether production, over the last 160 000 years on the Iberian Margin. The originality of this project lies in its double approach: on the one hand, with the acquisition of Uk'37 and TEX86 sedimentary records from the Iberian Margin, and on the other hand with the use of a coupled physics-biogeochemistry regional model to simulate these temperature proxies for 3 climate modes: at present, during the last glacial maximum, and during Heinrich Stadials. The comparison of biomarker results with those from modeling tests of production scenarios provided the following conclusions. Uk'37 does record annual mean SSTs, whereas TEX86 shows a priori too high temperature for this area. The formulation of a regional calibration for TEX86 index enables to obtain coherent past annual mean SSTs. The best location to apply both paleothermometers on the Iberian Margin is the Shackleton site. After refined analysis of multiproxy signal timings, TEX86 production seems to take place at intermediate depth, potentially by archaean communities coming from the Mediterranean Sea. Latitudinal thermal gradient variations are quantified, and glacial/interglacial surface and intermediate water masses reorganizations during 'Heinrich like' events are considered
Evidence for surfactant production by the haloarchaeon Haloferax sp. MSNC14 in hydrocarbon-containing media by Ikram Djeridi( )

1 edition published in 2013 in English and held by 2 WorldCat member libraries worldwide

Influence des processus de bio-perturbation sur le devenir des marqueurs lipidiques dans des sédiments marins côtiers by Sarah Caradec( Book )

2 editions published between 2003 and 2007 in French and held by 2 WorldCat member libraries worldwide

Biodégradation des hydrocarbures en milieux sursalés by Yannick Corsellis( )

2 editions published in 2017 in French and held by 2 WorldCat member libraries worldwide

This work performed on a thalassohaline hypersaline lake firstly considered seasonal dynamics of microbial communities (flow cytometry and MiSeq on 16S rRNA). Despite salinity fluctuations (15.5-32 %), a microbiome core highly stable at the genus level (97.2 ± 2.1 %) and dominated by Haloquadratum (40.3-57.4 %) and Salinibacter (4.9-21.8 %) was described. Interestingly, some halotolerant phylotypes exhibited rapid growths during dilutions episodes. In a controversial context concerning high salinity effects on hydrocarbons (HC) biodegradation, a study was conducted on close to salts-saturation brines (31 %) to gain insight into the fate of oil and it effects on active microbial communities after 15- and 30-days incubations. Significant oil biodegradation (12.8 %) was detected only after a 30-days incubation in LOM-amended microcosms while phylotypes belonging to Halobacteriaceae (Haloarcula, Halobacterium and Halorubrum) appeared as major active phylotypes. However, these low rates suggested that oil biodegradation should be lower under in situ conditions (lower temperature). Thus, among biostimulation approaches (mineral (-NS) or organic (-DS) amendments; dilution) used to improve self-cleaning processus, DS- or NS-amendments added to diluted brines (27.7 % to 14.0 %) allowed high attenuation rates of aliphatic HC with 97.8 % and 54.5 % respectively. Bacterial phylotypes belonging to Marinobacter and Flavobacteriaceae (e.g. Psychroflexus) were detected in NS- and DS-amended microcosms in which petroleum biodegradation occurred. This strategy will have, however, to be tested in other hypersaline systems (natural or industrial) in order to test its operational efficiency
Influence des paramètres environnementaux sur la biosynthèse d'éthers de glycérol bactériens : étude de modèles biologiques et exemples d'applications (paléo)environnementales by Arnauld Vinçon-Laugier( )

1 edition published in 2017 in French and held by 1 WorldCat member library worldwide

Some Bacteria synthesize particular phospholipids, called glycerol ether lipids (AGE) which have a chemical structure at the intersection of the Bacteria and Archea domains. The singular nature of these lipids and their thermostable chemical structure allow them to be well preserved in the environment following bacterial lysis, and suggest their potential to constitute good biogeochemical and/or environmental biomarkers. However, very little information is currently available concerning the modes of formation and the role of AGEs in bacterial membranes. In this thesis, we studied the lipid composition of various pure strains of anaerobic sulfate-reducing bacteria able to synthesize AGEs, grown under various controlled conditions of temperature, pH and salinity. Various structural modifications of AGE were observed in response to variations in growth conditions, some of which being specific to, and linearly correlated with, changes in temperature or salinity. The results demonstrate the involvement of AGEs in membrane adaptation to changes in the physico-chemical conditions, and suggest the use of the structural distribution of AGEs in natural samples as an indicator of environmental conditions. The analysis of the AGE content of samples from different actual and past ecosystems, allowed confirming the potential of AGEs to be used as indicators of variations of (paleo)environmental conditions
Eutrophisation des zones humides : conséquences pour la qualité, la décomposition des plantes aquatiques et les flux de carbone by Charlotte Grasset( )

1 edition published in 2015 in French and held by 1 WorldCat member library worldwide

Eutrophication is a current threat for wetlands. This phD thesis aims at determining the role of the abiotic parameters of eutrophication, mainly the phosphorus content, 1) on aquatic plant quality, 2) on aquatic plant decomposition, and 3) on carbon fluxes. 1. Three aquatic plant species representative of the Grime strategies, i.e. competitive, ruderal and stress tolerant, were collected in wetlands dispatched along a phosphorus gradient. For the three species, water content of populations increased with the nutrient content of the habitat. Carbon allocation (starch and/or lignin) also varied according to habitat. 2. The three species were collected and decomposed in wetlands dispatched along a nutrient gradient. Aquatic plant quality significantly affected their decomposition, in particular the ruderal and competitive species were more rapidly decomposed when they grew in nutrient rich sites. 3. Daytime CO2 and CH4 fluxes were measured in 6 floristic zones. Daytime CO2 emissions were negatively correlated with net primary productivity and CH4 emissions were positively correlated. The abundance of floating vegetation also increased CH4 emissions probably because macroalgae and to a lower extent vascular plants with floating leaves favor anoxic conditions. Eutrophication may affect aquatic plant chemical composition and increase their decomposition rate. Moreover, in eutrophic wetlands, floating vegetation may affect carbon fluxes because of their quality, their decomposition rate and the quantities produced, and indirectly because of their location in water column. Therefore the eutrophication should be taken into account in the global C budgets of softwater ecosystems
Variabilité climatique de la dernière période glaciaire en Europe : apports des tétraéthers méthylés et indicateurs associés by Lise Sanchi( )

1 edition published in 2013 in English and held by 1 WorldCat member library worldwide

In order to better understand the sensibility of the European continent to climate changes, the potential of branched tetraether lipids, as bases of temperature and soil pH proxies, has been studied in two sedimentary archives. These two marine sediment cores have been chosen for their location at the mouth of major rivers (Danube and paleo Channel river) on both sides of the ancient Fennoscandian ice sheet. Indeed, they enable to get records containing information integrated at large drainage basin scale, since the last glacial cycle. Thus, continuous temperature reconstructions of the last glacial period in Europe, based on branched tetraethers extracted from these cores, are presented. These records are carefully interpreted, notably because of the uncertainties on the tetraether producers and their likely production in the aquatic environment. The high temporal resolution of the reconstruction however enables insights into the last glacial abrupt climate variability, with temperature estimates of Heinrich events and Dansgaard-Oeschger cycles, and especially, quantitative estimations in central eastern Europe. Moreover, the reconstruction of past soil pH in this part of the continent is investigated. Last, an automated purification method for archaeal and bacterial tetraethers in soils and sediments has been developed in order to contribute to enhancing the time resolution of paleosequences based on tetraether biomarkers
Préparation et vieillissement de matières organiques en contexte archéologique : approche analytique et expérimentale by Julien Perthuison( )

1 edition published in 2020 in French and held by 1 WorldCat member library worldwide

The present PhD thesis was devoted to the alteration processes affecting organic substances in an archaeological context, and aimed at providing analytical and experimental keys to investigate the nature of the alteration processes, to identify new molecular tools indicators of archaeological alteration processes and to interpret the impact of these processes on the molecular signatures of these organic materials. Following the development of a laboratory ageing experimental protocol able to reproduce “natural” alteration of archaeological organic substances, we could establish that cross reactions between ingredients (esters of fatty acids, terpenoids) result in the formation oligo/polymeric material worth to be investigated by means of chemical degradation reactions. Additionally, investigation of archaeological organic substances was carried out. Thus, dipterocarpaceae resins from two Asian shipwrecks from the XIInd Century and birch bark tar used to fix Neolithic ceramics have been identified. New triterpenoid biomarkers resulting from the sedimentary anaerobic degradation of parent triterpenoids (resins) and markers indicative of intense thermal treatment (tar) have been characterized
Variabilité climatique et environnementale du dernier cycle glaciaire en Méditerranée occidentale : apports des nouveaux biomarqueurs organiques by Nina Davtian( )

1 edition published in 2019 in French and held by 1 WorldCat member library worldwide

The aim of my PhD is to better understand the genesis of signals based on archaeal and bacterial membrane lipids, tetraethers, in coastal marine environments by studying two adjacent sedimentary archives taken from the Gulf of Lions and covering the last glacial cycle. These archives were taken from the relatively shallow upper continental slope, which receives substantial terrigenous inputs during glacial periods. The study site thus has accumulation rates of about one meter per thousand years during glacial periods, which allows me to study the abrupt variability of Quaternary climates in addition to their longer-term variability. First, I have considerably improved the analysis of tetraethers, by adopting a new method for isomer separation and by optimizing the analytical instrument and signal detection. Second, I have tested a novel oceanic paleothermometer based on hydroxylated tetraethers (RI-OH index) for the first time in the western Mediterranean Sea. Third, I have studied the origins of tetraethers and their responses to sea level variations. The novel oceanic paleothermometer gives particularly encouraging results despite terrigenous inputs. However, bacterial tetraethers have mixed origins and complex, non linear responses to sea level variations. Possible explanations include the complex sedimentary dynamics of the Gulf of Lions and biases in tetraether-based signals
GéoMicrobiologie de la méthanogenèse dans les schistes immatures du bassin de Paris by Margaux Meslé( )

1 edition published in 2013 in French and held by 1 WorldCat member library worldwide

The exploitation of natural unconventional resources in substitution for petroleum is one of the challenges of the 21st century. In situ microbial transformation of these resources in methane is one of the most promising pathway currently developed, although its application needs to be demonstrated. My objectives were to demonstrate the existence of a microbial conversion into methane of the organic matter (OM) of immature shales, and to quantify it in order to extrapolate the potential for methane production of the rocks at the sedimentary basin scale. A method of detection and monitoring of methanogenic consortia from paper shales in microcosms, combining quantitative PCR, GC-FID and Rock-Eval pyrolysis, was developed and validated. It was used to study the spatial distribution of methanogens in paper shales of the Paris Basin and to demonstrate the methanization of the OM of these rocks. The results show the conversion of the soluble fractions of the OM (bitumen) by methanogenic consortia isolated from shales, but also the transformation of a more complex fraction (kerogen). No strict correlation was established between lithology and presence of active methanogens, which makes the extrapolation of methane production to the basin scale more difficult. However, the localization of methanogens in both OM-rich and OM-poor zones constitute an advantage in the perspective of an economic exploitation of these resources. This work demonstrates a great potential for microbial methane production in the Paris Basin and paves the way to studies of economic feasibility and profitability on the scale of a production site
Dynamique de la matière organique dans la Seine : approche globale et moléculaire by Alexandre Thibault( )

1 edition published in 2018 in French and held by 1 WorldCat member library worldwide

Les estuaires sont des écosystèmes importants pour l'environnement et l'économie et sont le lieu de nombreuse transformation de la matière organique (MO). La dynamique de la MO dans les estuaires est complexe, et est rarement étudiée à l'échelle moléculaire. L'objectif principal de cette étude est de contraindre la dynamique de la MO dans l'estuaire de Seine. Pour cela, cinq campagnes ont été réalisées dans l'ensemble de l'estuaire et ont permis l'analyse de la MO dans l'ensemble de ses compartiments (dissous - MOD, particulaire - MOP et sédimentaire). La MO a été caractérisée au niveau global (composition élémentaire et isotopique), au niveau structural (résonance magnétique nucléaire du carbone) et au niveau moléculaire (lipides et thermochimiolyse). L'ensemble des techniques ont pu montrer que chaque compartiment avait des propriétés chimiques très différentes : la MOD est enrichie en MO aquatique dégradée, alors que la MOP et la MO sédimentaire sont plus terrigènes. Le bouchon vaseux semble avoir un impact majeur sur la qualité de la MO, notamment grâce à des bactéries dégradant fortement la MO terrigène dans la MOP et augmentant la proportion de MO aquatique. De plus, les sédiments de l'estuaire de Seine n'enregistrent pas la composition totale de la MOP, mais sont enrichis en MO terrigène, moins labile. Enfin, lors de l'enfouissement de la MO sédimentaire, cette dernière s'enrichit en MO terrigène
Diagenèse précoce et préservation de la matière organique sédimentaire en milieu salé alcalin : cas du Lac Dziani Dzaha (Mayotte) by Ivan Jovović( )

1 edition published in 2020 in French and held by 1 WorldCat member library worldwide

Adaptations à la vie sous haute pression hydrostatique chez les microorganismes piézophiles, l'exemple de Thermococcus barophilus by Anaïs Cario( )

1 edition published in 2013 in French and held by 1 WorldCat member library worldwide

Deep marine and continental environments represent the major ecosystems on Earth. They are colonized by organisms named piezophiles, adapted to high pressures of the deep biosphere, conditions that inhibit the growth of surface organisms. My objectives were to elucidate the special features of adaptation to high hydrostatic pressures. My model of study was a piezophilic microorganism isolated from a deep-sea vent; Thermococcus barophilus strain MP, which grows optimally at a pressure of 400 times the atmospheric pressure. I characterized the specific adaptation of two cellular compartments amongst the most sensitive to pressure: membranes and proteome. My results show that strain MP accumulates stress molecules in conditions of low pressure, which mean T. barophilus proteome is adapted to high pressure conditions. This is the first demonstration of structural adaptation in a piezophile, and also shows that T. barophilus is a true piezophile. Besides, I proved membrane adaptation mechanisms in response to pressure and temperature. These mechanisms are based on homeoviscous adaptation of lipids composition. This adaptation is unique and involves three different mechanisms: the regulation of the di-/tetraether ratio, the modulation of lipid unsaturation, and the insertion of neutral lipids in the membrane structure. These results brought me to propose a new membrane model for the piezophilic strain T. barophilus. Before confirming these observations as a possible piezophilic trait of adaptation, this study needs to be extended to other piezophilic organisms
Caractérisation de substances naturelles en contexte archéologique : apport des études moléculaires, isotopiques et de la datation au 14C by Blandine Courel( )

1 edition published in 2016 in French and held by 1 WorldCat member library worldwide

Ces travaux d'archéométrie concernent l'étude moléculaire par GC-MS de marqueurs lipidiques (biomarqueurs) préservés au sein de sols archéologiques et de substances végétales impliquées en tant qu'ingrédients dans la confection d'artefacts. Des analyses complémentaires en isotopie du carbone de composés individuels et des mesures de datation au 14C (AMS MICADAS) de la matière organique totale des sols, d'extraits lipidiques et d'un composé individuel (miliacine) ont également été effectuées. Cette approche a permis:- de montrer l'existence de la culture de millet dès l'âge du Bronze en Alsace, les sols associés à cette culture et leur contenu organique ayant été piégés et préservés dans des silos à grains enterrés datés de l'âge du Fer.- d'identifier la nature de structures archéologiques comme étant d'anciennes latrines et une aire de stabulation de bétail via l'identification de stéroïdes fécaux.- d'établir des critères chimiotaxonomiques fiables basés sur l'analyse des lipides pour l'authentification de résines de styrax et de liquidambars.- d'identifier la nature d'une résine issue de Styrax officinalis ayant été incorporée dans l'enduit organique ornant un crâne décoré (IXème millénaire av. J.-C., site de Nahal Hemar, Israël).- de mettre en évidence l'emploi de brai de bouleau comme agent collant lors de la confection d'un bijou daté du Premier âge du Fer
 
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French (20)

English (2)