Consulta: creatorFacets:"Garnier, Matthieu"
Registros recuperados: 18
Data/hora: 10/06/2024 07:42:38

Screening and selection of growth-promoting bacteria for Dunaliella cultures
Provedor de dados: 5
Autores: Le Chevanton, Myriam; Garnier, Matthieu; Bougaran, Gael; Schreiber, Nathalie; Lukomska, Ewa; Berard, Jean-baptiste; Fouilland, E.; Bernard, Olivier; Cadoret, Jean-paul.
Previous studies have demonstrated that bacteria influence microalgal metabolism, suggesting that the selection and characterization of growth-promoting bacteria should offer a new strategy for improving industrial algal cultivation. In the present study, 48 cultivable bacteria were isolated from marine microalgae species and identified using 16S rRNA phylogenetic analysis. The recovered bacteria were found to be members of the α- and γ-Proteobacteria, Cytophaga–Flavobacterium–Bacteroides (CFB) and gram-positive monophyletic clusters. To address the effect of these bacteria on the growth of Dunaliella sp. individually, an experimental high-throughput tool was developed to simultaneously compare replicated associations. A two-step approach was used to...
Tipo: Text
Palavras-chave: Microalgae; Dunaliella; Bacteria; Interaction; Bacterial diversity.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00142/25334/24768.pdf

Use comparative proteomics on a selected microalgae provides candidates for biofuel production.
Provedor de dados: 5
Autores: Garnier, Matthieu; Carrier, Gregory; Rogniaux, Helene; Nicolau, Elodie; Bougaran, Gael; Saint-jean, Bruno; Cadoret, Jean-paul.
Microalgae are photosynthetic microorganisms that have an extraordinary diversity which biotechnological potential is just beginning to be explored. Microalgae in biotechnology are presently the focus of an unprecedented surge in interest and investment worldwide. Understanding microalgal lipid accumulation under nitrogen starvation is of major interest for feedstocks, food and biofuel production. Although studies have been performed in model species, to this day it is critical to understand through particular mechanisms of biotechnological species. Tisochrysis lutea is traditionally used for aquaculture feed and presents advantages for lipid production. The wild type strain and a lipid over-accumulating selected mutant were used to perform the first...
Tipo: Text
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00176/28735/27203.pdf

Effects of nitrogen limitation on Dunaliella sp.–Alteromonas sp. interactions: from mutualistic to competitive relationships.
Provedor de dados: 5
Autores: Le Chevanton, Myriam; Garnier, Matthieu; Lukomska, Ewa; Schreiber, Nathalie; Cadoret, Jean-paul; Saint-jean, Bruno; Bougaran, Gael.
Interactions between photosynthetic and non-photosynthetic microorganisms play an essential role in natural aquatic environments and the contribution of bacteria and microalgae to the nitrogen cycle can lead to both competitive and mutualistic relationships. Nitrogen is considered to be, with phosphorus and iron, one of the main limiting nutrients for primary production in the oceans and its availability experiences large temporal and geographical variations. For these reasons, it is important to understand how competitive and mutualistic interactions between photosynthetic and heterotrophic microorganisms are impacted by nitrogen limitation. In a previous study performed in batch cultures, the addition of a selected bacterial strain of Alteromonas sp....
Tipo: Text
Palavras-chave: Interactions; Nitrogen limitation; Microalgae; Bacteria; Chemostat; Dissolved organic matter (DOM); Dunaliella.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00344/45529/45087.pdf

Comparative proteomics reveals proteins impacted by nitrogen deprivation in wild-type and high lipid-accumulating mutant strains of Tisochrysis lutea
Provedor de dados: 5
Autores: Garnier, Matthieu; Carrier, Gregory; Rogniaux, Helene; Nicolau, Elodie; Bougaran, Gael; Saint-jean, Bruno; Cadoret, Jean-paul.
Understanding microalgal lipid accumulation under nitrogen starvation is of major interest for biomass feedstock, food and biofuel production. Using a domesticated oleaginous algae Tisochrysis lutea, we performed the first comparative proteomic analysis on the wild type strain and a selected lipid over-accumulating mutant. 2-DE analysis was made on these strains cultured in two metabolic conditions, with and without nitrogen deprivation, which revealed significant differences in proteomes according to both strain and nitrogen availability. Mass spectrometry allowed us to identify 37 proteins that were differentially expressed between the two strains, and 17 proteins regulated by nitrogen starvation concomitantly with lipid accumulation. The proteins...
Tipo: Text
Palavras-chave: Microalgae; Biotechnology; Lipid; Nitrogen; Proteomic; Selection.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00179/29012/27470.pdf

Comparative Transcriptome of Wild Type and Selected Strains of the Microalgae Tisochrysis lutea Provides Insights into the Genetic Basis, Lipid Metabolism and the Life Cycle
Provedor de dados: 5
Autores: Carrier, Gregory; Garnier, Matthieu; Le Cunff, Loic; Bougaran, Gael; Probert, Ian; De Vargas, Colomban; Corre, E; Cadoret, Jean-paul; Saint-jean, Bruno.
The applied exploitation of microalgae cultures has to date almost exclusively involved the use of wild type strains, deposited over decades in dedicated culture collections. Concomitantly, the concept of improving algae with selection programs for particular specific purposes is slowly emerging. Studying since a decade an economically and ecologically important haptophyte Tisochrysis lutea (Tiso), we took advantage of the availability of wild type (Tiso-Wt) and selected (Tiso-S2M2) strains to conduct a molecular variations study. This endeavour presented substantial challenges: the genome assembly was not yet available, the life cycle unknown and genetic diversity of Tiso-Wt poorly documented. This study brings the first molecular data in order to set up...
Tipo: Text
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00175/28662/27089.pdf

How haptophytes microalgae mitigate vitamin B-12 limitation
Provedor de dados: 5
Autores: Nef, Charlotte; Jung, Sebastien; Mairet, Francis; Kaas, Raymond; Grizeau, Dominique; Garnier, Matthieu.
Vitamin B-12 (cobalamin) can control phytoplankton development and community composition, with around half of microalgal species requiring this vitamin for growth. B-12 dependency is determined by the absence of cobalamin-independent methionine synthase and is unrelated across lineages. Despite their important role in carbon and sulphur biogeochemistry, little is known about haptophytes utilization of vitamin B-12 and their ability to cope with its limitation. Here we report the first evaluation of B-12 auxotrophy among this lineage based on molecular data of 19 species from 9 families. We assume that all species encode only a B-12-dependent methionine synthase, suggesting ubiquitous B-12 auxotrophy in this phylum. We further address the effect of...
Tipo: Text
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00504/61523/65398.pdf

Microalgae, Functional Genomics and Biotechnology
Provedor de dados: 5
Autores: Cadoret, Jean-paul; Garnier, Matthieu; Saint-jean, Bruno.
Microalgae have been studied for decades, but a new wave of research has recently begun as part of the search for renewable and sustainable energy sources. For economic optimization, microalgal biomass is being considered as a whole (main products and co-products) in an overall 'biorefinery' concept Applications of microalgae cover a broad spectrum, including the food and (livestock) feed industries, bio-energy, cosmetics, healthcare and environmental restoration or protection. In the field of biotechnology, the access to genomic data is playing a growing role. As the cost of sequencing strategies has fallen, studies of gene function at the transcript, protein and biosynthesis pathway levels have multiplied. Notably, sequencing and mass spectrometry...
Tipo: Text
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00125/23602/21477.pdf

Use of a lipid rich strain reveals mechanisms of nitrogen limitation and carbon partitioning in the haptophyte Tisochrysis lutea
Provedor de dados: 5
Autores: Garnier, Matthieu; Bougaran, Gael; Pavlovic, Marija; Berard, Jean-baptiste; Carrier, Gregory; Charrier, Aurelie; Le Grand, Fabienne; Lukomska, Ewa; Rouxel, Catherine; Schreiber, Nathalie; Cadoret, Jean-paul; Rogniaux, Helene; Saint-jean, Bruno.
Haptophytes are a diverse monophyletic group with a worldwide distribution, known to be significantly involved in global climate regulation in their role as a carbon sink. Because nitrogen is a major limiting macronutrient for phytoplankton in oceans and for cultures of microalgae, understanding the involvement of nitrogen availability in haptophyte carbon partitioning is of global and biotechnological importance. Here, we made an ecophysiological study coupled with comprehensive large scale proteomic analysis to examine differences of behavior in reaction to nitrogen availability changes between a wild type strain of Tisochrysis lutea (WTc1) and a mutant strain (2Xc1) known to accumulate more storage lipids. Strains were grown in chemostats and studied...
Tipo: Text
Palavras-chave: Algae; Isochrysis; Lipids; Nitrogen; Reverse genomic: proteomic.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00356/46702/46904.pdf

Gametogenic cycle and reproductive effort of the tropical blacklip pearl oyster, Pinctada margaritifera (Bivalvia : Pteriidae), cultivated in Takapoto atoll (French Polynesia)
Provedor de dados: 5
Autores: Pouvreau, Stephane; Gangnery, Aline; Tiapari, Jerome; Lagarde, Franck; Garnier, Matthieu; Bodoy, Alain.
The gametogenic cycle and the reproductive effort of the blacklip pearl oyster, Pinctada margaritifera, cultivated in Takapoto lagoon were studied for a 1-year period (March 1997-April 1998) by bimonthly observations of gonadal sections, dry tissue weights and gonadal index in a population of pearl oyster composed of three age-groups. pearl oysters attained sexual maturity in the end of their first year (height approximate to 40 mm), implying that P. margaritifera is a late-maturing species in comparison with other Pteriidae. This species was also confirmed to be a marked protandrous successive hermaphrodite in culture, with 100 % of males at first maturity and 75 % in older pearl oyster (height &gt; 120 mm). The general pattern of gametogenic activity,...
Tipo: Text
Palavras-chave: French Polynesia; Reproductive effort; Reproductive cycle; Tropical aquaculture; Gametogenesis; Blacklip pearl oyster; Polynésie française; Effort de reproduction; Cycle de reproduction; Aquaculture tropicale; Gamétogenèse; Huître perlière.
Ano: 2000
URL: http://archimer.ifremer.fr/doc/2000/publication-1391.pdf

Cobalamin Scarcity Modifies Carbon Allocation and Impairs DMSP Production Through Methionine Metabolism in the Haptophyte Microalgae Tisochrysis lutea
Provedor de dados: 5
Autores: Nef, Charlotte; Henry, Céline; Nicolau, Elodie; Bérard, Jean-baptiste; Hervé, Fabienne; Caruana, Amandine; Kaas, Raymond; Mairet, Francis; Garnier, Matthieu.
Cobalamin (vitamin B12) is a cobalt-containing enzymatic cofactor involved in methionine synthesis. Provided only by select bacteria and archaea in marine systems, this vitamin is known to limit primary production in different oceanic areas. Understanding the consequences of cobalamin limitation on phytoplankton physiology is of great interest, notably for cobalamin-dependent haptophytes that significantly contribute to oceanic carbon fixation and sulfur cycle through dimethyl sulfonio propionate (DMSP) synthesis. Here, the effect of cobalamin limitation was compared to nitrogen limitation on the model haptophyte Tisochrysis lutea grown in chemostats, combining comparative proteomics with the analysis of major macromolecules and specific osmolytes. Our...
Tipo: Text
Palavras-chave: Cobalamin; Vitamin B-12; Haptophyte microalgae; Tisochrysis lutea; DMSP; Chemostat; Comparative proteomics; Metabolism.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00654/76575/77711.pdf

Molecular and phenotypic characterization of Vibrio aestuarianus subsp francensis subsp nov., a pathogen of the oyster Crassostrea gigas
Provedor de dados: 5
Autores: Garnier, Matthieu; Labreuche, Yannick; Nicolas, Jean-louis.
Eleven Vibrio isolates invading the hemolymph of live and moribund oysters (Crassostrea gigas) collected in the field and from a hatchery in France, were characterized by a polyphasic approach. Phylogenetic analysis of 16S rRNA, gyrB and toxR genes indicated high homogeneity between these strains and the Vibrio aestuarianus type strain (ATCC35048(T)), and confirmed previous 16S rRNA analysis. In contrast, DNA:DNA hybridization was from 61% to 100%, while phenotypic characters and virulence tests showed a large diversity between the strains. Nevertheless, several common characters allowed the isolates to be distinguished from the reference strain. On the basis of several distinct phenotypic characteristics, it is proposed to establish two subspecies within...
Tipo: Text
Palavras-chave: Polyphasic approach; Summer mortalities; Crassostrea gigas; Pathogen; French isolates; Vibrio aestuarianus.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/publication-4961.pdf

Carbon conversion efficiency and population dynamics of a marine algae–bacteria consortium growing on simplified synthetic digestate: First step in a bioprocess coupling algal production and anaerobic digestion
Provedor de dados: 5
Autores: Vasseur, Christophe; Bougaran, Gael; Garnier, Matthieu; Hamelin, Jérôme; Leboulanger, Christophe; Le Chevanton, Myriam; Mostajir, Behzad; Sialve, Bruno; Steyer, Jean-philippe; Fouilland, Eric.
Association of microalgae culture and anaerobic digestion seems a promising technology for sustainable algal biomass and biogas production. The use of digestates for sustaining the growth of microalgae reduces the costs and the environmental impacts associated with the substantial algal nutrient requirements. A natural marine algae–bacteria consortium was selected by growing on a medium containing macro nutrients (ammonia, phosphate and acetate) specific of a digestate, and was submitted to a factorial experimental design with different levels of temperature, light and pH. The microalgal consortium reached a maximum C conversion efficiency (i.e. ratio between carbon content produced and carbon supplied through light photosynthetic C conversion and acetate)...
Tipo: Text
Palavras-chave: Optimization; Nannochloris; Heterotrophic bacteria; Anaerobic digestion; Bioenergy.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00085/19642/17419.pdf

Proteomic Analysis of the Chlorophyta Dunaliella New Strain AL-1 Revealed Global Changes of Metabolism during High Carotenoid Production
Provedor de dados: 5
Autores: Ben Amor, Faten; Elleuch, Fatma; Ben Hlima, Hajer; Garnier, Matthieu; Saint-jean, Bruno; Barkallah, Mohamed; Pichon, Chantal; Abdelkafi, Slim; Fendri, Imen.
The green microalgae Dunaliella genus is known for the production of high added value molecules. In this study, strain AL-1 was isolated from the Sebkha of Sidi El Hani (Sousse, Tunisia). This isolate was identified both morphologically and genetically via 18S rRNA gene sequence as a member of the genus Dunaliella. Strain AL-1 was found to be closely related to Dunaliella salina, Dunaliella quartolecta and Dunaliella polymorpha with more than 97% similarity. Response surface methodology was used to maximize carotenoid production by strain AL-1 by optimizing its growth conditions. The highest carotenoid content was obtained at salinity: 51, light intensity: 189.89 μmol photons·m−2·s−1, and nitrogen: 60 mg·L−1. Proteomic profiling, using two-dimensional gel...
Tipo: Text
Palavras-chave: Proteome; Dunaliella; 18S rRNA gene; Carotenoids; Bidimensional gel electrophoresis; Mass spectrometry.
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00402/51398/51973.pdf

High-affinity nitrate/nitrite transporter genes (Nrt2) in Tisochrysis lutea: identification and expression analyses reveal some interesting specificities of Haptophyta microalgae
Provedor de dados: 5
Autores: Charrier, Aurelie Georgette; Berard, Jean-baptiste; Bougaran, Gael; Carrier, Gregory; Lukomska, Ewa; Schreiber, Nathalie; Fournier, Flora; Charrier, Aurelie; Rouxel, Catherine; Garnier, Matthieu; Cadoret, Jean-paul; Saint-jean, Bruno.
Microalgae have a diversity of industrial applications such as feed, food ingredients, depuration processes and energy. However, microalgal production costs could be substantially improved by controlling nutrient intake. Accordingly, a better understanding of microalgal nitrogen metabolism is essential. Using in silico analysis from transcriptomic data concerning the microalgae Tisochrysis lutea, four genes encoding putative high-affinity nitrate/nitrite transporters (TlNrt2) were identified. Unlike most of the land plants and microalgae, cloning of genomic sequences and their alignment with complementary DNA (cDNA) sequences did not reveal the presence of introns in all TlNrt2 genes. The deduced TlNRT2 protein sequences showed similarities to NRT2...
Tipo: Text
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00253/36467/35044.pdf

Evidence for the involvement of pathogenic bacteria in summer mortalities of the Pacific oyster Crassostrea gigas
Provedor de dados: 5
Autores: Garnier, Matthieu; Labreuche, Yannick; Garcia, Celine; Robert, Maeva; Nicolas, Jean-louis.
A study was conducted to investigate the involvement of bacteria in oyster mortalities during summer. Moribund and apparently healthy oysters were sampled during mortality events along the French coast and in rearing facilities, usually when temperature reached 19 degrees C or higher, and oysters were in the gonadal maturation phase. Hemolymph samples were aseptically withdrawn and submitted to bacteriological analysis. In healthy oysters, bacteria colonized hernolymph at low concentrations depending on the location. In most moribund oysters, bacteria were present in hemolymph and other tissues. These bacterial populations were more often diverse in oysters originating from the open sea than from facilities where animals were generally infected by a single...
Tipo: Text
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/publication-2406.pdf

Allocation du carbone et métabolisme azoté chez l'haptophyte Tisochrysis lutea
Provedor de dados: 5
Autores: Garnier, Matthieu.
The aim of this thesis is to improve knowledge on mechanisms involved in the response to nitrogen limitation and in lipid accumulation in the microalgae haptophyte Tisochrysis lutea. The wild type strain and a lipid accumulating mutant strain were grown under different nitrogen limitation and starvation and analyzed by functional genomics. Four genes of high-affinity nitrate/nitrite transporter (Nrt2) were identified and characterized to reveal the mechanisms involved in mineral absorption in this species. Transcriptomes of both strains were sequenced and proteins affected by nitrogen starvation and differentially expressed between the two strains were identified. We so identified the functions regulated by nitrogen deficiency and potentially involved in...
Tipo: Text
Palavras-chave: Microalgues; Métabolisme; Azote; Carbone; Lipides; Genomique fonctionelle; Protéomique; Transcriptomique; Microalgae; Metabolism; Nitrogen; Carbon; Lipids; Functional genomics; Proteomics; Transcriptomics.
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00353/46378/46000.pdf

Growth of the black-lip pearl oyster, Pinctada margaritifera, in suspended culture under hydrobiological conditions of Takapoto lagoon (French Polynesia)
Provedor de dados: 5
Autores: Pouvreau, Stephane; Tiapari, Jerome; Gangnery, Aline; Lagarde, Franck; Garnier, Matthieu; Teissier, Hinano; Haumani, G; Buestel, Dominique; Bodoy, Alain.
Growth of the black-lip pearl oyster, Pinctada margaritifera var. cumingi, was studied for an annual cycle, from March 1997 to April 1998, in the lagoon of Takapoto atoll (Tuamotu archipelago, French Polynesia). Growth in shell and in tissue were measured every 15 days on three successive age groups of cultivated pearl oysters. At the same time, hydrobiological parameters (temperature, salinity, oxygen concentration, suspended particulate matter), known to have influence on bivalve growth, were followed each week during culture. No seasonal trend was observed in hydrobiological parameters, except for temperature which varied between 26 degrees C and 31 degrees C. The potential food for pearl oysters (particulate organic matter, POM, mg l(-1)) was slightly...
Tipo: Text
Palavras-chave: Pearl culture; Matter in suspension; Biochemical composition; Length weight relations ship; Tropical lagoon; Growth; Pinctada margaritifera.
Ano: 2000
URL: http://archimer.ifremer.fr/doc/2000/publication-381.pdf

Adaptation to Cold and Proteomic Responses of the Psychrotrophic Biopreservative Lactococcus piscium Strain CNCM I-4031
Provedor de dados: 5
Autores: Garnier, Matthieu; Matamoros, Sebastien; Chevret, Didier; Pilet, Marie-france; Leroi, Francoise; Tresse, Odile.
There is considerable interest in the use of psychrotrophic bacteria for food biopreservation and in the understanding of cold adaptation mechanisms. The psychrotrophic biopreservative Lactococcus piscium strain CNCM I-4031 was studied for its growth behavior and proteomic responses after cold shock and during cold acclimation. Growth kinetics highlighted the absence of growth latency after cold shock, suggesting a very high promptness in cold adaptation, a behavior that has never been described before for lactic acid bacteria (LAB). A comparative proteomic analysis was applied with two-dimensional gel electrophoresis (2-DE), and upregulated proteins were identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Both cold shock and cold...
Tipo: Text
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00019/13047/10150.pdf