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8 results on '"Linda Guentas"'

1. Potential of Halophytes-Associated Microbes for the Phytoremediation of Metal-Polluted Saline Soils

Author

Pauline Bonaventure, Linda Guentas, Valérie Burtet-Sarramegna, and Hamid Amir

Subjects
halophytes, PGP microbes, metal phytoremediation, bacteria, fungi, Technology, Engineering (General). Civil engineering (General), TA1-2040, Biology (General), QH301-705.5, Physics, QC1-999, Chemistry, QD1-999
Abstract

Saline ecosystems are often the target of spills and releases of pollutants such as metals, as many industrial companies settle in or around these areas. Metal pollution is a major threat for humans and ecosystems. In line with sustainable development, nature-based solutions and biological tools such as phytoremediation offer eco-friendly and low-cost solutions to remove metals or limit their spread in the environment. Many plant-growth-promoting (PGP) effects are frequently prospected in plant-associated microbes such as the production of auxins, siderophores, or extracellular polymeric substances to enhance phytoremediation. Halophytes are nowadays presented as good phytoremediators for metal-contaminated saline environments such as coastal regions, but little is known about the potential of their associated microbes in the bioaugmentation of this technique. Here, we review the studies that focused on halophytes-associated microbes and their plant-growth-promotion capacities. Moreover, we discuss the limitation and applicability of bioaugmented phytoremediation in saline ecosystems.

Published
2023
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2. Spatial distribution of microbial communities in the shallow submarine alkaline hydrothermal field of the Prony Bay, New Caledonia

Author

Emmanuelle Gérard, Marianne Quéméneur, Céline Pisapia, Bernard Ollivier, Gaël Erauso, Christophe Monnin, Martine Gérard, Anne Postec, Claude Payri, Valérie Chavagnac, Jérôme Hamelin, Linda Guentas-Dombrowsky, Bernard Pelletier, Méline Bes, Nan Mei, and Bénédicte Ménez

Subjects
Desulfobacterales, biology, Chemistry, Firmicutes, Ecology, Geochemistry, biology.organism_classification, Agricultural and Biological Sciences (miscellaneous), Desulfovibrionales, chemistry.chemical_compound, Microbial population biology, 13. Climate action, Methanosarcinales, Carbonate, Seawater, 14. Life underwater, Bay, Ecology, Evolution, Behavior and Systematics
Abstract

The shallow submarine hydrothermal field of the Prony Bay (New Caledonia) discharges hydrogen- and methane-rich fluids with low salinity, temperature (

Published
2014
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3. Mineralizing Filamentous Bacteria from the Prony Bay Hydrothermal Field Give New Insights into the Functioning of Serpentinization-Based Subseafloor Ecosystems

Author

Martine Gérard, Susan Q. Lang, Bernard Pelletier, Bénédicte Ménez, Linda Guentas, Anne Postec, Marianne Quéméneur, Céline Pisapia, Claude Payri, Léna Lecourt, Emmanuelle Gérard, Christophe Monnin, Gaël Erauso, Institut de Physique du Globe de Paris ( IPGP ), Institut national des sciences de l'Univers ( INSU - CNRS ) -IPG PARIS-Université Paris Diderot - Paris 7 ( UPD7 ) -Université de la Réunion ( UR ) -Centre National de la Recherche Scientifique ( CNRS ), Institut de minéralogie, de physique des matériaux et de cosmochimie ( IMPMC ), Muséum National d'Histoire Naturelle ( MNHN ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut de recherche pour le développement [IRD] : UR206-Centre National de la Recherche Scientifique ( CNRS ), University of South Carolina [Columbia], University IRD Noumea, Institut de Recherche pour le Développement ( IRD [Nouvelle-Calédonie] ), Écosystémique des communautés récifales et de leurs usages dans le Pacifique insulaire ( CoReUS ), Géosciences Environnement Toulouse ( GET ), Institut de Recherche pour le Développement ( IRD ) -Université Paul Sabatier - Toulouse 3 ( UPS ) -Observatoire Midi-Pyrénées ( OMP ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire Matériaux Polymères Interfaces Environnement Marin - EA 4323 ( MAPIEM ), Université de Toulon ( UTLN ), Université de Nouvelle-Calédonie, Nouméa, Institut méditerranéen d'océanologie ( MIO ), Institut de Recherche pour le Développement ( IRD ) -Aix Marseille Université ( AMU ) -Université de Toulon ( UTLN ) -Centre National de la Recherche Scientifique ( CNRS ), Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD [Nouvelle-Calédonie]), Écosystémique des communautés récifales et de leurs usages dans le Pacifique insulaire (CoReUS), Géosciences Environnement Toulouse (GET), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Laboratoire Matériaux Polymères Interfaces Environnement Marin - EA 4323 (MAPIEM), Université de Toulon (UTLN), Université de la Nouvelle-Calédonie (UNC), Institut méditerranéen d'océanologie (MIO), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Institut de sciences exactes et appliquées (ISEA), BUNC, Pole ID, Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Université Paris Diderot - Paris 7 (UPD7)-IPG PARIS-Institut national des sciences de l'Univers (INSU - CNRS), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Centre National d'Études Spatiales [Toulouse] (CNES), Université de la Nouvelle Calédonie (UNC), and Centre National de la Recherche Scientifique (CNRS)-Université de Toulon (UTLN)-Aix Marseille Université (AMU)-Institut de Recherche pour le Développement (IRD)

Subjects
0301 basic medicine, Microbiology (medical), [SDE] Environmental Sciences, Firmicutes, Earth science, 030106 microbiology, serpentinization, Microbiology, [ CHIM ] Chemical Sciences, Hydrothermal circulation, [PHYS] Physics [physics], [ SDE ] Environmental Sciences, 03 medical and health sciences, chemistry.chemical_compound, Microbial ecology, [ SDV.MP ] Life Sciences [q-bio]/Microbiology and Parasitology, Dissolved organic carbon, [CHIM] Chemical Sciences, [CHIM]Chemical Sciences, Ecosystem, 14. Life underwater, [SDV.MP] Life Sciences [q-bio]/Microbiology and Parasitology, Original Research, [PHYS]Physics [physics], [ PHYS ] Physics [physics], biology, Acetothermia, Ecology, organic carbon, deep life, biology.organism_classification, 030104 developmental biology, [SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology, chemistry, 13. Climate action, [SDE]Environmental Sciences, Methanosarcinales, Carbonate, Omnitrophica, alkaline hydrothermalism, Bay
Abstract

Despite their potential importance as analogs of primitive microbial metabolisms, the knowledge of the structure and functioning of the deep ecosystems associated with serpentinizing environments is hampered by the lack of accessibility to relevant systems. These hyperalkaline environments are depleted in dissolved inorganic carbon (DIC), making the carbon sources and assimilation pathways in the associated ecosystems highly enigmatic. The Prony Bay Hydrothermal Field (PHF) is an active serpentinization site where, similar to Lost City (Mid-Atlantic Ridge), high-pH fluids rich in H-2 and CH4 are discharged from carbonate chimneys at the seafloor, but in a shallower lagoonal environment. This study aimed to characterize the subsurface microbial ecology of this environment by focusing on the earliest stages of chimney construction, dominated by the discharge of hydrothermal fluids of subseafloor origin. By jointly examining the mineralogy and the microbial diversity of the conduits of juvenile edifices at the micrometric scale, we find a central role of uncultivated bacteria belonging to the Firmicutes in the ecology of the PHF. These bacteria, along with members of the phyla Acetothermia and Omnitrophica, are identified as the first chimneys inhabitants before archaeal Methanosarcinales. They are involved in the construction and early consolidation of the carbonate structures via organomineralization processes. Their predominance in the most juvenile and nascent hydrothermal chimneys, and their affiliation with environmental subsurface microorganisms, indicate that they are likely discharged with hydrothermal fluids from the subseafloor. They may thus be representative of endolithic serpentinization-based ecosystems, in an environment where DIC is limited. In contrast, heterotrophic and fermentative microorganisms may consume organic compounds from the abiotic by-products of serpentinization processes and/or from life in the deeper subsurface. We thus propose that the Firmicutes identified at PHF may have a versatile metabolism with the capability to use diverse organic compounds from biological or abiotic origin. From that perspective, this study sheds new light on the structure of deep microbial communities living at the energetic edge in serpentinites and may provide an alternative model of the earliest metabolisms.

Published
2017
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4. Characterization and anti-biofilm activity of extracellular polymeric substances produced by the marine biofilm-forming bacterium Pseudoalteromonas ulvae strain TC14

Author

Annick Ortalo-Magné, Gérald Culioli, Linda Guentas-Dombrowsky, Yves Blache, Ahmad Fahs, Maëlle Molmeret, Florence Brian-Jaisson, Stéphane Cérantola, Laboratoire Insulaire du Vivant et de l'Environnement (LIVE), and Université de la Nouvelle-Calédonie (UNC)

Subjects
0301 basic medicine, [SDV]Life Sciences [q-bio], 030106 microbiology, Aquatic Science, Microscopy, Atomic Force, Polysaccharide, Applied Microbiology and Biotechnology, Biofouling, 03 medical and health sciences, Extracellular polymeric substance, Pseudoalteromonas, Marine bacteriophage, 14. Life underwater, Water Science and Technology, Glucan, chemistry.chemical_classification, biology, Polysaccharides, Bacterial, Biofilm, biology.organism_classification, 030104 developmental biology, Biochemistry, chemistry, Biofilms, Water Microbiology, Bacteria
Abstract

This study investigated soluble (Sol-EPS), loosely bound (LB-EPS), and tightly bound extracellular polymeric substances (TB-EPS) harvested from biofilm and planktonic cultures of the marine bacterium Pseudoalteromonas ulvae TC14. The aim of the characterization (colorimetric methods, FTIR, GC-MS, NMR, HPGPC, and AFM analyses) was to identify new anti-biofilm compounds; activity was assessed using the BioFilm Ring Test®. A step-wise separation of EPS was designed, based on differences in water-solubility and acidity. An acidic fraction was isolated from TB-EPS, which strongly inhibited biofilm formation by marine bacterial strains in a concentration-dependent manner. The main constituents of this fraction were characterized as two glucan-like polysaccharides. An active poly(glutamyl-glutamate) fraction was also recovered from TB-EPS. The distribution of these key EPS components in Sol-EPS, LB-EPS, and TB-EPS was distinct and differed quantitatively in biofilm vs planktonic cultures. The anti-biofilm potential of the fractions emphasizes the putative antifouling role of EPS in the environment.

Published
2016
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5. Selective affinity of l-histidine immobilized onto poly(ethylene–vinyl alcohol) hollow-fiber membranes for various oligoglucuronans

Author

Linda Guentas, Anne-Sophie Pirlet, Bernard Courtois, Mookambeswaran A. Vijayalakshmi, Josiane Courtois, Olivier Pitiot, and Alain Heyraud

Subjects
chemistry.chemical_classification, Vinyl alcohol, Chromatography, Chemistry, Organic Chemistry, General Medicine, Uronic acid, Degree of polymerization, Oligosaccharide, Polysaccharide, Glucuronic acid, Biochemistry, Analytical Chemistry, chemistry.chemical_compound, Membrane, Organic chemistry, Histidine
Abstract

A new species of oligoglucuronan was previously extracted from a polysaccharide crude fraction produced by a Sinorhizobium meliloti mutant strain, by chromatography on l -histidine immobilized onto poly(ethylene–vinyl alcohol) (PEVA) hollow-fiber membranes. Until now, only one specific species of oligoglucuronan was selectively adsorbed on the membranes with immobilized histidine. In this work, the specific membranes, commonly used to purify proteins, were tested on different non-ionic and anionic carbohydrate components. We determined only anionic oligosaccharides are selectively retained on these membranes. The affinity between the l -His–PEVA membranes and oligoglucuronans varying in the degree of polymerization and the degree of substitution by acetyl residues was studied.

Published
1999
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6. Separation of low-molecular-mass acetylated glucuronans on l-histidine immobilized onto poly(ethylene–vinyl alcohol) hollow-fiber membranes

Author

Linda Guentas, Anne-Sophie Pirlet, M.A Vijalayakshmi, Olivier Pitiot, Alain Heyraud, Josiane Courtois, and Bernard Courtois

Subjects
chemistry.chemical_classification, Vinyl alcohol, Chromatography, Molecular mass, Organic Chemistry, General Medicine, Uronic acid, Oligosaccharide, Biochemistry, Analytical Chemistry, chemistry.chemical_compound, Membrane, chemistry, Succinic acid, Selective adsorption, Organic chemistry, Histidine
Abstract

Low-molecular-mass polysaccharides produced by Rhizobia strains may be composed of a mixture of cyclic (1→2)-β- d -glucans substitued by sn -1-phosphoglycerol, succinic acid or methylmalonic acid or unsubstituted, and of oligosaccharides produced de novo or by degradation of the high-molecular-mass polysaccharides. The Sinorhizobium meliloti M5N1CS mutant strain (NCIMB 40472) produces unsubstituted cyclic glucans and these substituted by sn -1-phosphoglycerol, a wide variety of oligoglucuronans and high-molecular-mass glucuronans partially acetylated at the C2 and/or the C3 position. Until now, the purification of oligoglucuronans with a specific acetylation degree was not possible. In this work, we have studied the possibility of using l -histidine immobilized onto poly(ethylene–vinyl alcohol) hollow-fiber membranes for the separation of acetylated oligoglucuronans. Membranes with immobilized histidine known for purification of proteins based on dipole interaction were studied for the selective adsorption of glucuronans with discrimination of acetylation.

Published
1998
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7. Production of a glucoglucuronan by a rhizobia strain infecting alfalfa. Structure of the repeating unit

Author

Patrice Pheulpin, Bernard Courtois, Linda Guentas, Claude Gey, Alain Heyraud, and Josiane Courtois

Subjects
Stereochemistry, Chemical structure, Disaccharide, Bacterial growth, Biochemistry, Rhizobia, chemistry.chemical_compound, Biopolymers, Glucuronic Acid, Structural Biology, Molecular Biology, Nuclear Magnetic Resonance, Biomolecular, Growth medium, Strain (chemistry), biology, Polysaccharides, Bacterial, General Medicine, Hydrogen-Ion Concentration, biology.organism_classification, Glucose, chemistry, Fermentation, Rhizobium, Medicago sativa
Abstract

The Rhizobium sp. T1 strain. which induces nodule formation on alfalfa and clover roots, produces, during growth, an extracellular polysaccharide composed of D-glucose and D-glucuronic acid noted glucoglucuronan. During the bacterial growth, the pH of the medium decreases slightly. The control of pH in the growth medium slightly reduces the glucoglucuronan production. Under the conditions tested in the present work, the weight-average molecular weight of the polymers produced with or without pH control are similar: Mw approximately 2 x 10(6); the repeating unit determined by chemical and NMR analyses corresponds to the disaccharide: --> 3)-beta-D-GlcpA-(1-->4)-beta-D-Glcp-(1 -->.

Published
2000

8. The zoonotic pathogen Leptospira interrogans mitigates environmental stress through cyclic-di-GMP-controlled biofilm production

Author

Julien Fernandes, Emilie Bierque, Dominique Girault, Malia Kainiu, Mathieu Picardeau, Joëlle Vinh, Nicolas Eskenazi, Anthony Douyère, Heike Bähre, Marie-Estelle Soupé-Gilbert, Roman Thibeaux, Cyrille Goarant, Unité de Recherche et d'Expertise Leptospirose - Leptospirosis Research and Expertise Unit [Nouméa, Nouvelle-Calédonie] (UREL), Institut Pasteur de Nouvelle-Calédonie, Réseau International des Instituts Pasteur (RIIP)-Réseau International des Instituts Pasteur (RIIP), BioImagerie Photonique – Photonic BioImaging (UTechS PBI), Institut Pasteur [Paris] (IP), Hannover Medical School [Hannover] (MHH), Institut de sciences exactes et appliquées (ISEA), Université de la Nouvelle-Calédonie (UNC), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL), Spectrométrie de Masse Biologique et Protéomique (USR3149 / FRE2032) (SMBP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Centre Collaborateur FAO/OMS pour l'épidémiologie de la leptospirose, Centre National de Référence de la Leptospirose - National Reference Center Leptospirosis (CNR), Biologie des Spirochètes / Biology of Spirochetes, This work was funded by a postdoctoral fellowship awarded by the AXA Research Fund (reference: 15-AXA-PDOC-037). Lastly, we thank the UTechS Photonic BioImaging facility (Imagopole, C2RT, Institut Pasteur) funded by the French National Research Agency (France BioImaging, ANR-10–INSB–04, Investments for the Future programme)., The authors thank Johann Peltier, Nadia Benaroudj, Robert Antony Gaultney, Linda Guentas, Arnaud Tarantola and Catherine Inizan for technical assistance and critical discussions. The authors are indebted to Professor Jean-Marc Ghigo for critical discussions and support at the start of this project. We thank Julien Colot and the Laboratoire de Biologie Médicale at Centre Hospitalier Territorial Gaston Bourret for granting access to their MALDI-TOF facilities. We also thank the CRESICA consortium for granting access to the electron microscopy facilities., ANR-10-INBS-0004,France-BioImaging,Développment d'une infrastructure française distribuée coordonnée(2010), and Institut Pasteur [Paris]

Subjects
Cyclic di-GMP, Bacterial Zoonoses, Virulence, Applied Microbiology and Biotechnology, Microbiology, lcsh:Microbial ecology, Article, 03 medical and health sciences, chemistry.chemical_compound, Spatio-Temporal Analysis, Bacterial Proteins, Stress, Physiological, Guanosine monophosphate, Animals, Humans, Cyclic GMP, 030304 developmental biology, 0303 health sciences, biology, Environmental microbiology, 030306 microbiology, Phosphoric Diester Hydrolases, Escherichia coli Proteins, Biofilm, Biofilm matrix, Gene Expression Regulation, Bacterial, biochemical phenomena, metabolism, and nutrition, biology.organism_classification, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, 3. Good health, chemistry, Biofilms, Mutation, biology.protein, lcsh:QR100-130, Diguanylate cyclase, Leptospira interrogans, Phosphorus-Oxygen Lyases, Bacteria, Biotechnology
Abstract

The zoonotic bacterium Leptospira interrogans is the aetiological agent of leptospirosis, a re-emerging infectious disease that is a growing public health concern. Most human cases of leptospirosis result from environmental infection. Biofilm formation and its contribution to the persistence of virulent leptospires in the environment or in the host have scarcely been addressed. Here, we examined spatial and time-domain changes in biofilm production by L. interrogans. Our observations showed that biofilm formation in L. interrogans is a highly dynamic process and leads to a polarized architecture. We notably found that the biofilm matrix is composed of extracellular DNA, which enhances the biofilm’s cohesiveness. By studying L. interrogans mutants with defective diguanylate cyclase and phosphodiesterase genes, we show that biofilm production is regulated by intracellular levels of bis-(3′–5′)-cyclic dimeric guanosine monophosphate (c-di-GMP) and underpins the bacterium’s ability to withstand a wide variety of simulated environmental stresses. Our present results show how the c-di-GMP pathway regulates biofilm formation by L. interrogans, provide insights into the environmental persistence of L. interrogans and, more generally, highlight leptospirosis as an environment-borne threat to human health.

Published
2020
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