Author: "Nicolas Menguy" - Searchworks@Jio Institute Digital Library Search Results

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212 results on '"Nicolas Menguy"'

1. Exploring the Substitution of Fe(III) by Gd(III) in Nanomagnetite

Author: Carolina Guida, Anthony Chappaz, Agnieszka Poulain, Jean-Marc Grenèche, Alexandre Gloter, Nicolas Menguy, Nathaniel Findling, and Laurent Charlet
Subjects: Chemical technology, TP1-1185
Published: 2024
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2. Metastable liquid immiscibility in the 2018–2021 Fani Maoré lavas as a mechanism for volcanic nanolite formation

Author: Simon Thivet, Luiz Pereira, Nicolas Menguy, Étienne Médard, Pauline Verdurme, Carole Berthod, David Troadec, Kai-Uwe Hess, Donald B. Dingwell, and Jean-Christophe Komorowski
Subjects: Geology, QE1-996.5, Environmental sciences, GE1-350
Abstract: Abstract Nanoscale liquid immiscibility is observed in the 2018–2021 Fani Maoré submarine lavas (Comoros archipelago). Heat transfer calculations, Raman spectroscopy, scanning and transmission electron microscopy reveal that in contrast to thin (500 µm) outer rims of homogeneous glassy lava (rapidly quenched upon eruption, >1000 °C s−1), widespread liquid immiscibility is observed in thick (1 cm) inner lava rims (moderately quenched, 1–1000 °C s−1), which exhibit a nanoscale coexistence of Si- and Al-rich vs. Ca-, Fe-, and Ti-rich melt phases. In this zone, rapid nanolite crystallization contrasts with the classical crystallization process inferred for the slower cooled (
Published: 2023
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3. Promoting Selective CO2 Electroreduction to Formic Acid in Acidic Medium with Low Potassium Concentrations under High CO2 Pressure

Author: Florian Lhostis, Ngoc‐Huan Tran, Gwenaëlle Rousse, Sandrine Zanna, Nicolas Menguy, and Marc Fontecave
Subjects: Bi-based electrocatalysts, CO2 electroreduction, acidic electrolyte, Formic acid, High pressure cell, Industrial electrochemistry, TP250-261, Chemistry, QD1-999
Abstract: Abstract Electrocatalytic CO2 reduction reaction (CO2RR) offers a sustainable pathway for the production of chemicals and fuels. Acidic electrolysis has been shown to be a promising strategy in order to avoid CO2 loss via the formation (bi)carbonate during reaction. Previous studies have been carried out in ambient CO2 pressure systems and have stressed the importance of adding high concentration of alkali cation (K+) in the catholyte to inhibit the hydrogen evolution reaction (HER) and achieve higher selectivity of CO2RR. Herein, CO2 reduction to HCOOH was performed in strong acid (pH 1) using a dendritic bismuth catalyst in a home‐designed high‐pressure electrochemical cell. At a CO2 pressure of 30 bar, we could achieve a high Faradaic efficiency of 100 % at 100 mA cm−2 at a KCl concentration of 3.0 M. With this first system that combines high pressure of CO2 and highly acidic catholyte, we show that pressurization offers an appropriate strategy to limit both HER and K+ dependence. Indeed we obtained a Faradaic efficiency of 34 % in the absence of K+ cations and 75–80 % in the presence of 1.0 M KCl under an applied current density of 100 mA cm−2.
Published: 2024
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4. Angular orientation between the cores of iron oxide nanoclusters controls their magneto–optical properties and magnetic heating functions

Author: Enzo Bertuit, Nicolas Menguy, Claire Wilhelm, Anne-Laure Rollet, and Ali Abou-Hassan
Subjects: Chemistry, QD1-999
Abstract: Oriented attachment of nanoscale building blocks into hierarchical structures offers vast opportunities to engineer nanomaterial structure-property relationships. Here, the misalignment of crystal plane orientations between iron oxide nanoclusters is shown to govern their magneto–optical properties and magnetic heating functions.
Published: 2022
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5. Comparative Investigation of Red and Orange Roman Tesserae: Role of Cu and Pb in Colour Formation

Author: Cécile Noirot, Laurent Cormier, Nadine Schibille, Nicolas Menguy, Nicolas Trcera, and Emiliano Fonda
Subjects: copper red, glass colouration, Roman glass, nanoparticles, electron microscopy, XANES, Archaeology, CC1-960
Abstract: This study aims at the characterisation of red and orange glass tesserae from the 4th-century Roman villa of Noheda (Spain). Due to the limited number of analyses available for such ancient materials, many questions remain unanswered about the production processes in the Roman period. Six samples were chosen for their hue variations, including two samples showing banded patterns of red and orange. Differences in copper speciation were investigated by X-ray absorption spectroscopy and compared with colour and compositional variations obtained by EPMA. The shapes and sizes of colouring crystals could be investigated using scanning and transmission electron microscope imaging. The brown-red colour is due to metallic copper nano-particles and corresponds to a low-copper and low-lead group usually described in the literature. The orange samples and bands are coloured by copper oxide Cu2O nanoparticles with remaining Cu+ in the glass and have greater contents of Cu. Compositional analyses reveal that the same base glass is used in the red and orange bands with additions of Cu, Sn, Pb and probable Fe. Furthermore, based on our results and on the literature review, a high-copper low-lead group of glasses highlights the variability of compositions observed in cuprite colours.
Published: 2022
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6. Biogeochemical Niche of Magnetotactic Cocci Capable of Sequestering Large Polyphosphate Inclusions in the Anoxic Layer of the Lake Pavin Water Column

Author: Cécile C. Bidaud, Caroline L. Monteil, Nicolas Menguy, Vincent Busigny, Didier Jézéquel, Éric Viollier, Cynthia Travert, Fériel Skouri-Panet, Karim Benzerara, Christopher T. Lefevre, and Élodie Duprat
Subjects: magnetotactic bacteria (MTB), magnetosomes, redox and chemical gradients, morphotype diversity, P sequestration, electron microscopy, Microbiology, QR1-502
Abstract: Magnetotactic bacteria (MTB) are microorganisms thriving mostly at oxic–anoxic boundaries of aquatic habitats. MTB are efficient in biomineralising or sequestering diverse elements intracellularly, which makes them potentially important actors in biogeochemical cycles. Lake Pavin is a unique aqueous system populated by a wide diversity of MTB with two communities harbouring the capability to sequester not only iron under the form of magnetosomes but also phosphorus and magnesium under the form of polyphosphates, or calcium carbonates, respectively. MTB thrive in the water column of Lake Pavin over a few metres along strong redox and chemical gradients representing a series of different microenvironments. In this study, we investigate the relative abundance and the vertical stratification of the diverse populations of MTB in relation to environmental parameters, by using a new method coupling a precise sampling for geochemical analyses, MTB morphotype description, and in situ measurement of the physicochemical parameters. We assess the ultrastructure of MTB as a function of depth using light and electron microscopy. We evidence the biogeochemical niche of magnetotactic cocci, capable of sequestering large PolyP inclusions below the oxic–anoxic transition zone. Our results suggest a tight link between the S and P metabolisms of these bacteria and pave the way to better understand the implication of MTB for the P cycle in stratified environmental conditions.
Published: 2022
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7. Multi-Scale Investigation of Body-Glaze Interface in Ancient Ceramics

Author: Marie Godet, Gauthier Roisine, Emmie Beauvoit, Daniel Caurant, Odile Majérus, Nicolas Menguy, Olivier Dargaud, Anne Bouquillon, and Laurent Cormier
Subjects: ceramics, Renaissance, Palissy, body-glaze interface, TEM, SAED, HRTEM, Archaeology, CC1-960
Abstract: Bernard Palissy is a French Renaissance ceramist renowned for his masterpieces called Rustiques Figulines on which dozens of glazes of different chemistries (and thus firing behaviors) coexist harmoniously. This study aims at gathering information on the master procedure -never revealed- by investigating the body-glaze interface region (focusing on iron-colored honey transparent glaze-white body system). Optical and electron microscopies including transmission electron microscopy (TEM) are used to characterize the micro and nanostructure of both archaeological and replicas interfaces elaborated in controlled conditions (firing time, cooling rate, addition of Al in the glazing mixture). Both types of interfaces are comparable: a modified paste area from which are growing a relatively continuous layer of interfacial crystals identified as lead feldspars (K,Ca)PbAl2Si2O8 micro-sized single-crystals incorporating mullite 3Al2O3.2SiO2 nano-sized single-crystals. Modification of the firing parameters and removal of Al from the glazing mixture change essentially the interface extension and the micro-crystals morphology. By comparing archaeological and replica interfaces and considering previous studies, we can now state that Palissy was very likely adding clay (Al) in his frit. Moreover, he was probably working with a firing time of more than 1 h followed by slow cooling in the oven.
Published: 2019
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8. Interactions between magnetite and humic substances: redox reactions and dissolution processes

Author: Anneli Sundman, James M. Byrne, Iris Bauer, Nicolas Menguy, and Andreas Kappler
Subjects: Magnetite, Humic substances, Redox, Dissolution, Electron transfer, Environmental sciences, GE1-350, Chemistry, QD1-999
Abstract: Abstract Humic substances (HS) are redox-active compounds that are ubiquitous in the environment and can serve as electron shuttles during microbial Fe(III) reduction thus reducing a variety of Fe(III) minerals. However, not much is known about redox reactions between HS and the mixed-valent mineral magnetite (Fe3O4) that can potentially lead to changes in Fe(II)/Fe(III) stoichiometry and even dissolve the magnetite. To address this knowledge gap, we incubated non-reduced (native) and reduced HS with four types of magnetite that varied in particle size and solid-phase Fe(II)/Fe(III) stoichiometry. We followed dissolved and solid-phase Fe(II) and Fe(III) concentrations over time to quantify redox reactions between HS and magnetite. Magnetite redox reactions and dissolution processes with HS varied depending on the initial magnetite and HS properties. The interaction between biogenic magnetite and reduced HS resulted in dissolution of the solid magnetite mineral, as well as an overall reduction of the magnetite. In contrast, a slight oxidation and no dissolution was observed when native and reduced HS interacted with 500 nm magnetite. This variability in the solubility and electron accepting and donating capacity of the different types of magnetite is likely an effect of differences in their reduction potential that is correlated to the magnetite Fe(II)/Fe(III) stoichiometry, particle size, and crystallinity. Our study suggests that redox-active HS play an important role for Fe redox speciation within minerals such as magnetite and thereby influence the reactivity of these Fe minerals and their role in biogeochemical Fe cycling. Furthermore, such processes are also likely to have an effect on the fate of other elements bound to the surface of Fe minerals.
Published: 2017
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9. Protective Effect of Polyoxometalates in {Mo132}/Maghemite Binary Superlattices Under Annealing

Author: Romain Breitwieser, Adrien Garnier, Thomas Auvray, Anh-Tu Ngo, Benoit Baptiste, Nicolas Menguy, Anna Proust, Christophe Petit, Florence Volatron, and Caroline Salzemann
Subjects: binary superlattices, maghemite, polyoxometalates, magnetism, annealing, Chemistry, QD1-999
Abstract: The binary assembly DDA-{Mo132}/OA-γ-Fe2O3 (DDA = didodecyldimethylammonium, {Mo132} = [Mo132O372(CH3COO)30(H2O)72]42−, OA = oleic acid) constitutes one of the two examples in the literature of binary superlattices made of a mixing of nanocrystals and oxo-clusters. In a precedent work, we reported in details the preparation of such magnetic binary systems and studied the effect of the nature of the polyoxometalates (POMs) on the magnetic properties. In the present paper, we study the stability of this model binary assembly under heating at various temperatures. Indeed, especially if magnetic and/or transport properties are targeted, an annealing can be essential to change the phase of the nanocrystals in a more magnetic one and/or to desorb the organic capping of the nano-objects that can constitute an obstacle to the electronic communication between the nano-objects. We gave evidence that the maghemite organization in the binary assembly is maintained until 370°C under vacuum thanks to the presence of the POMs. This latter evolve in the phase MoO3, but still permits to avoid the aggregation of the nanocrystals as well as preserve their periodical arrangement. On the contrary, an assembly made of pure γ-Fe2O3 nanocrystals displays a clear aggregation of the nano-objects from 370°C, as attested by transmission and scanning electronic microscopies and confirmed by magnetic measurements. The stability of the magnetic nanocrystals in such POMs/nanocrystals assemblies opens the way to (i) the elaboration of new binary assemblies from POMs and numerous kinds of nanocrystals with a good control on the magnetic properties and to (ii) the investigation of new physical properties as exchange coupling, or magneto-transport in such systems.
Published: 2019
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10. Discovery of High Abundances of Aster-Like Nanoparticles in Pelagic Environments: Characterization and Dynamics

Author: Jonathan Colombet, Hermine Billard, Bernard Viguès, Stéphanie Balor, Christelle Boulé, Lucie Geay, Karim Benzerara, Nicolas Menguy, Guy Ilango, Maxime Fuster, François Enault, Corinne Bardot, Véronique Gautier, Angia Sriram Pradeep Ram, and Télesphore Sime-Ngando
Subjects: pleomorphic nanoparticles, femtoplankton, femtoplanktonic diversity, aquatic ecosystems, aquatic ecology, Microbiology, QR1-502
Abstract: This study reports the discovery of Aster-Like Nanoparticles (ALNs) in pelagic environments. ALNs are pleomorphic, with three dominant morphotypes which do not fit into any previously defined environmental entities [i.e., ultramicro-prokaryotes, controversed nanobes, and non-living particles (biomimetic mineralo-organic particles, natural nanoparticles or viruses)] of similar size. Elemental composition and selected-area electron diffraction patterns suggested that the organic nature of ALNs may prevail over the possibility of crystal structures. Likewise, recorded changes in ALN numbers in the absence of cells are at odds with an affiliation to until now described viral particles. ALN abundances showed marked seasonal dynamics in the lakewater, with maximal values (up to 9.0 ± 0.5 × 107 particles·mL−1) reaching eight times those obtained for prokaryotes, and representing up to about 40% of the abundances of virus-like particles. We conclude that (i) aquatic ecosystems are reservoirs of novel, abundant, and dynamic aster-like nanoparticles, (ii) not all virus-like particles observed in aquatic systems are necessarily viruses, and (iii) there may be several types of other ultra-small particles in natural waters that are currently unknown but potentially ecologically important.
Published: 2019
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11. Ecotoxicological Studies of ZnO and CdS Nanoparticles on Chlorella vulgaris Photosynthetic Microorganism in Seine River Water

Author: Alice da Rocha, Nicolas Menguy, Claude Yéprémian, Alain Couté, and Roberta Brayner
Subjects: polyol process, cds, zno, ecotoxicology, chlorella vulgaris, Chemistry, QD1-999
Abstract: Seine river water was used as natural environmental medium to study the ecotoxicological impact of ZnO and CdS nanoparticles and Zn2+ and Cd2+ free ions using Chlorella vulgaris as a biological target. It was demonstrated by viability tests and photosynthetic activity measurements that free Zn2+ (IC50 = 2.7 × 10−4 M) is less toxic than free Cd2+ and ZnO nanoparticles (IC50 = 1.4 × 10−4 M). In the case of cadmium species, free Cd2+ (IC50 = 3.5 × 10−5 M) was similar to CdS nanoparticles (CdS-1: IC50 = 1.9 × 10−5 M and CdS-2: IC50 = 1.9 × 10−5 M), as follows: CdS > Cd2+ > ZnO > Zn2+. Adenosine-5’-triphosphate (ATP) assay and superoxide dismutase (SOD) enzymatic activity confirmed these results. Transmission electron microscopy (TEM), coupled with energy-dispersive X-ray spectroscopy (EDS), confirmed the internalization of CdS-1 nanoparticles after 48 h of contact with Chlorella vulgaris at 10−3 M. With a higher concentration of nanoparticles (10−2 M), ZnO and CdS-2 were also localized inside cells.
Published: 2020
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12. Magnetotactic Coccus Strain SHHC-1 Affiliated to Alphaproteobacteria Forms Octahedral Magnetite Magnetosomes

Author: Heng Zhang, Nicolas Menguy, Fuxian Wang, Karim Benzerara, Eric Leroy, Peiyu Liu, Wenqi Liu, Chunli Wang, Yongxin Pan, Zhibao Chen, and Jinhua Li
Subjects: magnetotactic cocci, magnetosome, biomineralization, octahedron, coordinated FISH-SEM, TEM, Microbiology, QR1-502
Abstract: Magnetotactic bacteria (MTB) are morphologically and phylogenetically diverse prokaryotes. They can form intracellular chain-assembled magnetite (Fe3O4) or greigite (Fe3S4) nanocrystals each enveloped by a lipid bilayer membrane called a magnetosome. Magnetotactic cocci have been found to be the most abundant morphotypes of MTB in various aquatic environments. However, knowledge on magnetosome biomineralization within magnetotactic cocci remains elusive due to small number of strains that have been cultured. By using a coordinated fluorescence and scanning electron microscopy method, we discovered a unique magnetotactic coccus strain (tentatively named SHHC-1) in brackish sediments collected from the estuary of Shihe River in Qinhuangdao city, eastern China. It phylogenetically belongs to the Alphaproteobacteria class. Transmission electron microscopy analyses reveal that SHHC-1 cells formed many magnetite-type magnetosomes organized as two bundles in each cell. Each bundle contains two parallel chains with smaller magnetosomes generally located at the ends of each chain. Unlike most magnetotactic alphaproteobacteria that generally form magnetosomes with uniform crystal morphologies, SHHC-1 magnetosomes display a more diverse variety of crystal morphology even within a single cell. Most particles have rectangular and rhomboidal projections, whilst others are triangular, or irregular. High resolution transmission electron microscopy observations coupled with morphological modeling indicate an idealized model—elongated octahedral crystals, a form composed of eight {111} faces. Furthermore, twins, multiple twins and stack dislocations are frequently observed in the SHHC-1 magnetosomes. This suggests that biomineralization of strain SHHC-1 magnetosome might be less biologically controlled than other magnetotactic alphaproteobacteria. Alternatively, SHHC-1 is more sensitive to the unfavorable environments under which it lives, or a combination of both factors may have controlled the magnetosome biomineralization process within this unique MTB.
Published: 2017
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13. Quantitative mapping of calcium cell reservoirs in cyanobacteria at the submicrometer scale

Author: Karim, Benzerara, Sigrid, Görgen, Athar, Khan Monis, Franck, Chauvat, Katia, March, Nicolas, Menguy, Neha, Mehta, Fériel, Skouri-Panet, Sufal, Swaraj, Cynthia, Travert, Corinne, Cassier-Chauvat, and Elodie, Duprat
Published: 2023
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14. Hierarchical superparamagnetic metal–organic framework nanovectors as anti-inflammatory nanomedicines

Author: Heng Zhao, Saad Sene, Angelika M. Mielcarek, Sylvain Miraux, Nicolas Menguy, Dris Ihiawakrim, Ovidiu Ersen, Christine Péchoux, Nathalie Guillou, Joseph Scola, Jean-Marc Grenèche, Farid Nouar, Simona Mura, Florent Carn, Florence Gazeau, Eddy Dumas, Christian Serre, Nathalie Steunou, Institut des Matériaux Poreux de Paris (IMAP ), Département de Chimie - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut Lavoisier de Versailles (ILV), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Centre de résonance magnétique des systèmes biologiques (CRMSB), Université de Bordeaux (UB)-Centre National de la Recherche Scientifique (CNRS), Sorbonne Université (SU), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Saclay, Génétique Animale et Biologie Intégrative (GABI), AgroParisTech-Université Paris-Saclay-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Groupe d'Etude de la Matière Condensée (GEMAC), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS), Institut des Molécules et Matériaux du Mans (IMMM), Le Mans Université (UM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut Galien Paris-Saclay (IGPS), Institut de Chimie du CNRS (INC)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Matière et Systèmes Complexes (MSC), and Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)
Subjects: Biomedical Engineering, [CHIM]Chemical Sciences, General Materials Science, General Chemistry, General Medicine
Abstract: International audience; Among a plethora of drug nanocarriers, biocompatible nanoscale metal-organic frameworks (nanoMOFs) with a large surface area and an amphiphilic internal microenvironment have emerged as promising drug delivery platforms, mainly for cancer therapy. However, their application in biomedicine still suffers from shortcomings such as a limited chemical and/or colloidal stability and/or toxicity. Here, we report the design of a hierarchically porous nano-object (denoted as USPIO@MIL) combining a benchmark nanoMOF (that is, MIL-100(Fe)) and ultra-small superparamagnetic iron oxide (USPIO) nanoparticles (that is, maghemite) that is synthesized through a one-pot, cost-effective and environmentally friendly protocol. The synergistic coupling of the physico-chemical and functional properties of both nanoparticles confers to these nano-objects valuable features such as high colloidal stability, high biodegradability, low toxicity, high drug loading capacity as well as stimuli-responsive drug release and superparamagnetic properties. This bimodal MIL-100(Fe)/maghemite nanocarrier once loaded with anti-tumoral and anti-inflammatory drugs (doxorubicin and methotrexate) shows high anti-inflammatory and anti-tumoral activities. In addition, the USPIO@MIL nano-object exhibits excellent relaxometric properties and its applicability as an efficient contrast agent for magnetic resonance imaging is herein demonstrated. This highlights the high potential of the maghemite@MOF composite integrating the functions of imaging and therapy as a theranostic anti-inflammatory formulation.
Published: 2023

15. In Situ Synthesis of a Mesoporous MIL-100(Fe) Bacteria Exoskeleton

Author: Anastasia Permyakova, Alshaba Kakar, Jonathan Bachir, Effrosyni Gkaniatsou, Bernard Haye, Nicolas Menguy, Farid Nouar, Christian Serre, Nathalie Steunou, Thibaud Coradin, Francisco M. Fernandes, Clémence Sicard, Institut Lavoisier de Versailles (ILV), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Matériaux et Biologie (LCMCP-MATBIO), Laboratoire de Chimie de la Matière Condensée de Paris (LCMCP), Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut des Matériaux Poreux de Paris (IMAP ), Département de Chimie - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), ANR-19-CE08-0023,EMERGE,Conception de matériaux bio-hybrides associant entités biologiques et Metal-Organic Frameworks pour des applications environnementales(2019), and ANR-17-CE08-0009,CellsInFoams,Mousses macroporeuses cœur-coquille pour l'encapsulation de bactéries(2017)
Subjects: Synthesised, Two-component, Bacteria, Pseudomonas putida, General Chemical Engineering, Biomedical Engineering, Membrane integrity, Mesoporous, MIL-100, In-situ synthesis, Aqueous media, Exoskeleton (Robotics), Polycarboxylates, [CHIM]Chemical Sciences, General Materials Science, Cytology, Condition
Abstract: International audience; The mesoporous iron polycarboxylate MIL-100(Fe) was synthesized in the presence of Pseudomonas putida bacteria. The synthesis was performed under green conditions, i.e., pure aqueous media at 30 °C that were compatible with the preservation of the cell membrane integrity. Interestingly, the resulting biohybrid exhibited a very different microstructure than a physical mixture of the two components, as it led to the formation of a novel living material featuring an exoskeleton encapsulating individual bacteria cell. Remarkably, TEM and STEM observations on cross sections revealed that this shell was not directly in contact with the cell wall, suggesting the exopolysaccharides network promotes strong interactions with the MOF precursors, leading to high proximity between the two components.
Published: 2022

16. Engineering of Metal–Organic Frameworks/Gelatin Hydrogel Composites Mediated by the Coacervation Process for the Capture of Acetic Acid

Author: Subharanjan Biswas, Mohamed Haouas, Cátia Freitas, Carla Vieira Soares, Abeer Al Mohtar, Ali Saad, Heng Zhao, Georges Mouchaham, Carine Livage, Florent Carn, Nicolas Menguy, Guillaume Maurin, Moises L. Pinto, and Nathalie Steunou
Subjects: General Chemical Engineering, Materials Chemistry, General Chemistry
Published: 2022

17. In Operando Spectroscopic Ellipsometry Investigation of MOF Thin Films for the Selective Capture of Acetic Acid

Author: Sanchari Dasgupta, Subharanjan Biswas, Kevin Dedecker, Eddy Dumas, Nicolas Menguy, Bruno Berini, Bertrand Lavedrine, Christian Serre, Cédric Boissière, Nathalie Steunou, Institut Lavoisier de Versailles (ILV), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Groupe d'Etude de la Matière Condensée (GEMAC), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS), Centre de Recherche sur la Conservation (CRC ), Muséum national d'Histoire naturelle (MNHN)-Ministère de la Culture et de la Communication (MCC)-Centre National de la Recherche Scientifique (CNRS), Institut des Matériaux Poreux de Paris (IMAP ), Département de Chimie - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Matériaux Hybrides et Procédés (LCMCP-MHP ), Matériaux Hybrides et Nanomatériaux (LCMCP-MHN), Laboratoire de Chimie de la Matière Condensée de Paris (LCMCP), Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire de Chimie de la Matière Condensée de Paris (LCMCP), Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), and This work was supported by the Ecole Universitaire de recherche PSGS HCH Humanities, Creation, Heritage, Investissement d’Avenir ANR-17-EURE-0021 - Fondation des sciences du patrimoine. This work has been sponsored by the Ile-de-France Region in the framework of Respore, the Île-de-France network of Excellence in Porous Solids. The authors acknowledge Ali Saad for SEM experiments.
Subjects: Ellipsometry, adsorption, Thin films, [SDE]Environmental Sciences, [CHIM]Chemical Sciences, General Materials Science, Volatile organic compounds, MOFs
Abstract: International audience; The emission of polar volatile organic compounds (VOCs) is a major worldwide concern of air quality and equally impacts the preservation of cultural heritage (CH). The challenge is to design highly efficient adsorbents able to selectively capture traces of VOCs such as acetic acid (AA) in the presence of relative humidity (RH) normally found at storage in museums (40-80%). Although the selective capture of VOCs over water is still challenging, Metal-Organic Frameworks (MOFs) possess highly tunable features (Lewis, Bronsted or redox metal sites, functional groups, hydrophobicity…) suitable to selectively capture a large variety of VOCs. In this context, we have explored the adsorption efficiency of a series of MOFs thin films (ZIF-8(Zn), MIL-101(Cr) and UiO-66(Zr)-2CF3) for the selective capture of AA based on a UV/Vis and FT-IR spectroscopic ellip-sometry in operando study (2-6% of relative pressure of AA under 40% of RH), namely conditions close to the realistic envi-ronmental storage conditions of cultural artefacts. For that purpose, optical quality thin films of MOFs were prepared by dip-coating and their AA adsorption capacity and selectivity were evaluated under humid conditions by measuring the variation of the refractive index as a function of the vapor pressures while the chemical nature of the co-adsorbed analytes (water and AA) was identified by FT-IR ellipsometry. While thin films of ZIF-8(Zn) strongly degraded when exposed to AA/water va-pors, films of MIL-101(Cr) and UiO-66(Zr)-2CF3 present a high chemical stability under those conditions. It was shown that MIL-101(Cr) presents a high AA adsorption capacity due to its high pore volume, but exhibits a poor AA adsorption selectivi-ty under humid conditions. In contrast, UiO-66(Zr)-2CF3 was shown to overpass MIL-101(Cr) in terms of AA/ H2O adsorp-tion selectivity and AA adsorption/desorption cycling stability thanks to its high hydrophobic character, suitable pore size for adequate confinement and specific interactions.
Published: 2023

18. Collective magnetotaxis of microbial holobionts is optimized by the three-dimensional organization and magnetic properties of ectosymbionts

Author: Daniel M. Chevrier, Amélie Juhin, Nicolas Menguy, Romain Bolzoni, Paul E. D. Soto-Rodriguez, Mila Kojadinovic-Sirinelli, Greig A. Paterson, Rachid Belkhou, Wyn Williams, Fériel Skouri-Panet, Artemis Kosta, Hugo Le Guenno, Eva Pereiro, Damien Faivre, Karim Benzerara, Caroline L. Monteil, Christopher T. Lefevre, Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Cosmochimie [IMPMC] (IMPMC_COSMO), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Department of Earth Ocean and Ecological Sciences [Liverpool], University of Liverpool, Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), School of Geosciences [Edinburgh], University of Edinburgh, Institut de Microbiologie de la Méditerranée (IMM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), ALBA Synchrotron light source [Barcelone], ANR-21-CE02-0034,SymbioMAGNET,ETUDE DE LA BIODIVERSITE, DE L'ECOLOGIE ET DE L'EVOLUTION DE LA SYMBIOSE MAGNETOTACTIQUE(2021), and European Project: 797431,BioNanoMagnets
Subjects: Biomineralization, 40 magnetotactic bacteria, Multidisciplinary, [SDV]Life Sciences [q-bio], Collective magnetotaxis, Magnetosomes, biomineralization, Symbiosis, collective magnetotaxis, magnetosomes, Holobiont, symbiosis, holobiont
Abstract: Altres ajuts: D.M.C. and D.F. acknowledge awarded ALBA synchrotron beamtimes (Proposals 2018022677 and 2019023346), Mistral beamline staff for assistance in cryo-SXT experiments and CALIPSOplus funding for Proposal 2019023346. We acknowledge Soleil Synchrotron for beamtime awarded (Proposal 20191124) for experiments on the Hermes beamline (STXM-XMCD). Over the last few decades, symbiosis and the concept of holobiont-a host entity with a population of symbionts-have gained a central role in our understanding of life functioning and diversification. Regardless of the type of partner interactions, understanding how the biophysical properties of each individual symbiont and their assembly may generate collective behaviors at the holobiont scale remains a fundamental challenge. This is particularly intriguing in the case of the newly discovered magnetotactic holobionts (MHB) whose motility relies on a collective magnetotaxis (i.e., a magnetic field-assisted motility guided by a chemoaerotaxis system). This complex behavior raises many questions regarding how magnetic properties of symbionts determine holobiont magnetism and motility. Here, a suite of light-, electron- and X-ray-based microscopy techniques [including X-ray magnetic circular dichroism (XMCD)] reveals that symbionts optimize the motility, the ultrastructure, and the magnetic properties of MHBs from the microscale to the nanoscale. In the case of these magnetic symbionts, the magnetic moment transferred to the host cell is in excess (102 to 103 times stronger than free-living magnetotactic bacteria), well above the threshold for the host cell to gain a magnetotactic advantage. The surface organization of symbionts is explicitly presented herein, depicting bacterial membrane structures that ensure longitudinal alignment of cells. Magnetic dipole and nanocrystalline orientations of magnetosomes were also shown to be consistently oriented in the longitudinal direction, maximizing the magnetic moment of each symbiont. With an excessive magnetic moment given to the host cell, the benefit provided by magnetosome biomineralization beyond magnetotaxis can be questioned.
Published: 2023

19. Membrane-remodeling protein ESCRT-III homologs incarnate the evolution and morphogenesis of multicellular magnetotactic bacteria

Author: Wenyan Zhang, Jianwei Chen, Jie Dai, Shiwei Zhu, Hugo Le Guenno, Artemis Kosta, Hongmiao Pan, Xin-Xin Qian, Claire-Lise Santini, Nicolas Menguy, Xuegong Li, Yiran Chen, Jia Liu, Kaixuan Cui, Yicong Zhao, Guilin Liu, Eric Durand, Wei-Jia Zhang, Alain Roussel, Tian Xiao, Long-Fei Wu, Helmholtz-Zentrum Geesthacht (GKSS), Ming Hsieh Department of Electrical Engineering [Los Angeles], USC Viterbi School of Engineering, University of Southern California (USC)-University of Southern California (USC), Research Center for Proteome Analysis Key Lab of Proteomics, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Chinese Academy of Sciences [Beijing] (CAS), Yale School of Medicine [New Haven, Connecticut] (YSM), Centre d'Immunologie de Marseille - Luminy (CIML), Aix Marseille Université (AMU)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), CAS Key Laboratory of Marine Ecology and Environmental Science (KLMEES), CAS Institute of Oceanology (IOCAS), Chinese Academy of Sciences [Beijing] (CAS)-Chinese Academy of Sciences [Beijing] (CAS), Laboratoire de chimie bactérienne (LCB), Aix Marseille Université (AMU)-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), International Associated Laboratory of Evolution and Development of Magnetotactic Multicellular Organisms ( LIA-MagMC), Chinese Academy of Sciences [Beijing] (CAS)-Centre National de la Recherche Scientifique (CNRS), Xi'an Jiaotong University (Xjtu), Endothélium, valvulopathies et insuffisance cardiaque (EnVI), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Institut National de la Santé et de la Recherche Médicale (INSERM), Architecture et fonction des macromolécules biologiques (AFMB), and Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)
Subjects: [SDV.BID.EVO]Life Sciences [q-bio]/Biodiversity/Populations and Evolution [q-bio.PE]
Abstract: Endosomal sorting complex required transport (ESCRT) III proteins are essential for membrane remodeling and repair across all domains of life. Eukaryotic ESCRT-III and the cyanobacterial homologs PspA and Vipp1/Imm30 remodel membrane into vesicles, rings, filaments and tubular rods structures. Here our microscopy analysis showed that multicellular bacteria, referred to as magnetoglobules, possess multiple compartments including magnetosome organelles, polyphosphate granules, vesicles, rings, tubular rods, filaments and MVB-like structures. Therefore, membrane remodeling protein PspA might be required for the formation of these compartments, and contribute to the morphogenesis and evolution of multicellularity. To assess these hypotheses, we sequenced nine genomes of magnetoglobules and found a significant genome expansion compared to unicellular magnetotactic bacteria. Moreover, PspA was ubiquitous in magnetoglobules and formed a distinct clade on the tree of eubacterial and archaeal ESCRT-III. The phylogenetic feature suggested the evolution of magnetoglobules from a unicellular ancestor of deltaproteobacterium. Hetero-expression of ellipsoidal magnetoglobulepspA2gene alone inEscherichia coliresulted in intracellular membrane aggregation. GFP fusion labeling revealed polar location of PspA2 in rod-shaped unicells and regular interval location in filamentous cells. Cryo-electron tomography analysis showed filament bundle, membrane sacculus, vesicles and MVB-like structure in the cells expressing PspA2. Moreover, electron-dense area with a similar distribution as GFP-PspA2 foci in filamentous cells changed the inward orientation of the septum, which might interfere with the cell division. Collectively, these results show the membrane remodeling function of magnetoglobule PspA proteins, which may contribute to morphogenesis and the evolution of multicellularity of magnetotactic bacteria.
Published: 2022

20. Key gene networks that control magnetosome biomineralization in magnetotactic bacteria

Author: Peiyu Liu, Yue Zheng, Rongrong Zhang, Jinling Bai, Kelei Zhu, Karim Benzerara, Nicolas Menguy, Xiang Zhao, Andrew P Roberts, Yongxin Pan, and Jinhua Li
Subjects: Multidisciplinary
Abstract: Magnetotactic bacteria (MTB) are a group of phylogenetically and morphologically diverse prokaryotes that have the capability of sensing Earth's magnetic field via nanocrystals of magnetic iron minerals. These crystals are enclosed within intracellular membranes or organelles known as magnetosomes and enable a sensing function known as magnetotaxis. Although MTB were discovered over half a century ago, the study of the magnetosome biogenesis and organization remains limited to a few cultured MTB strains. Here, we present an integrative genomic and phenomic analysis to investigate the genetic basis of magnetosome biomineralization in both cultured and uncultured strains from phylogenetically diverse MTB groups. The magnetosome gene contents/networks of strains are correlated with magnetic particle morphology and chain configuration. We propose a general model for gene networks that control/regulate magnetosome biogenesis and chain assembly in MTB systems.
Published: 2022

21. Selenium Nanowire Formation by Reacting Selenate with Magnetite

Author: Agnieszka Poulain, Alejandro Fernandez-Martinez, Jean-Marc Greneche, Damien Prieur, Andreas C. Scheinost, Nicolas Menguy, Sarah Bureau, Valérie Magnin, Nathaniel Findling, Jakub Drnec, Isaac Martens, Marta Mirolo, Laurent Charlet, European Synchrotron Radiation Facility (ESRF), Institut des Sciences de la Terre (ISTerre), Université Joseph Fourier - Grenoble 1 (UJF)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-PRES Université de Grenoble-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Institut des Molécules et Matériaux du Mans (IMMM), Le Mans Université (UM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Helmholtz-Zentrum Dresden-Rossendorf (HZDR), European Synchroton Radiation Facility [Grenoble] (ESRF), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), and Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Gustave Eiffel-Université Grenoble Alpes (UGA)
Subjects: Nanowires, General Chemistry, [CHIM.MATE]Chemical Sciences/Material chemistry, Selenic Acid, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, Selenious Acid, Ferrosoferric Oxide, Selenium, Coal, Steel, Radioactive Waste, [CHIM.CRIS]Chemical Sciences/Cristallography, Environmental Chemistry, Adsorption, Selenium Compounds, Oxidation-Reduction, [SDU.STU.MI]Sciences of the Universe [physics]/Earth Sciences/Mineralogy
Abstract: International audience; The mobility of 79Se, a fission product of 235U and long-lived radioisotope, is an important parameter in the safety assessment of radioactive nuclear waste disposal systems. Nonradioactive selenium is also an important contaminant of drainage waters from black shale mountains and coal mines. Highly mobile and soluble in its high oxidation states, selenate (Se(VI)O42–) and selenite (Se(IV)O32–) oxyanions can interact with magnetite, a mineral present in anoxic natural environments and in steel corrosion products, thereby being reduced and consequently immobilized by forming low-solubility solids. Here, we investigated the sorption and reduction capacity of synthetic nanomagnetite toward Se(VI) at neutral and acidic pH, under reducing, oxygen-free conditions. The additional presence of Fe(II)aq, released during magnetite dissolution at pH 5, has an effect on the reduction kinetics. X-ray absorption spectroscopy analyses revealed that, at pH 5, trigonal gray Se(0) formed and that sorbed Se(IV) complexes remained on the nanoparticle surface during longer reaction times. The Se(0) nanowires grew during the reaction, which points to a complex transport mechanism of reduced species or to active reduction sites at the tip of the Se(0) nanowires. The concomitant uptake of aqueous Fe(II) and Se(VI) ions is interpreted as a consequence of small pH oscillations that result from the Se(VI) reduction, leading to a re-adsorption of aqueous Fe(II) onto the magnetite, renewing its reducing capacity. This effect is not observed at pH 7, where we observed only the formation of Se(0) with slow kinetics due to the formation of an oxidized maghemite layer. This indicates that the presence of aqueous Fe(II) may be an important factor to be considered when examining the environmental reactivity of magnetite.
Published: 2022

22. Angular Orientation between the Cores of Magnetic Iron Oxide Nanoclusters Controls their Properties and Functions

Author: Ali Abou-Hassan, Enzo Bertuit, nicolas Menguy, claire wilhelm, and anne-laure Rollet
Abstract: Oriented attachment of nanobricks into hierarchical multi-scale structures such as inorganic nanoclusters is one of the crystallization mechanisms that has revolutionized the field of nano and materials science. Herein, we show that the mosaicity, which measures the misalignment of crystal plane orientation between the nanobricks, governs their magneto-optical properties as well as the magnetic heating functions of iron oxide nanoclusters. Thanks to high-temperature and time-resolved microfluidics, we were able to isolate and characterize (structure, properties, function) the different intermediates involved in the diverse steps of the nanocluster’s formation, to propose a detailed dynamical mechanism of their formation and establish a clear correlation between changes in mosaicity at the nanoscale and their resulting physical properties. Finally, we demonstrate that their magneto-optical properties can be described using simple molecular theories.
Published: 2022

23. Intracellular silicification by early-branching magnetotactic bacteria

Author: Jinhua Li, Peiyu Liu, Nicolas Menguy, Xingliang Zhang, Jian Wang, Karim Benzerara, Lianjun Feng, Lei Sun, Yue Zheng, Fanqi Meng, Lin Gu, Eric Leroy, Jialong Hao, Xuelei Chu, Yongxin Pan, Chinese Academy of Sciences [Beijing] (CAS), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), College of Computer Science [Hangzhou] (HDU), Hangzhou Dianzi University (HDU), IMPMC_Cosmochimie (IMPMC_COSMO), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Chinese Academy of Agricultural Sciences (CAAS), State key laboratory of new ceramics and fine processing, Tsinghua University [Beijing] (THU), Institut de Chimie et des Matériaux Paris-Est (ICMPE), Institut de Chimie du CNRS (INC)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), State Key Laboratory of Lithospheric Evolution (SKL), Institute of Geology and Geophysics [Beijing] (IGG), Chinese Academy of Sciences [Beijing] (CAS)-Chinese Academy of Sciences [Beijing] (CAS), and University of Chinese Academy of Sciences [Beijing] (UCAS)
Subjects: Silicon, Multidisciplinary, Bacteria, Eukaryota, Magnetosomes, Silicon Dioxide, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Ferrosoferric Oxide, [SDU.STU.MI]Sciences of the Universe [physics]/Earth Sciences/Mineralogy
Abstract: International audience; Biosilicification—the formation of biological structures composed of silica—has a wide distribution among eukaryotes; it plays a major role in global biogeochemical cycles, and has driven the decline of dissolved silicon in the oceans through geological time. While it has long been thought that eukaryotes are the only organisms appreciably affecting the biogeochemical cycling of Si, the recent discoveries of silica transporter genes and marked silicon accumulation in bacteria suggest that prokaryotes may play an underappreciated role in the Si cycle, particularly in ancient times. Here, we report a previously unidentified magnetotactic bacterium that forms intracellular, amorphous silica globules. This bacterium, phylogenetically affiliated with the phylum Nitrospirota, belongs to a deep-branching group of magnetotactic bacteria that also forms intracellular magnetite magnetosomes and sulfur inclusions. This contribution reveals intracellularly controlled silicification within prokaryotes and suggests a previously unrecognized influence on the biogeochemical Si cycle that was operational during early Earth history.
Published: 2022

24. Diverse phylogeny and morphology of magnetite biomineralized by magnetotactic cocci

Author: Andrew P. Roberts, Yue Zheng, Fuxian Wang, Heng Zhang, Nicolas Menguy, Yongxin Pan, Yan Liu, Xiang Zhao, Jinhua Li, Lushan Wang, and Peiyu Liu
Subjects: Biomineralization, Geologic Sediments, Magnetotactic bacteria, Magnetosome, Biology, Microbiology, 03 medical and health sciences, Species Specificity, Phylogenetics, Phylogeny, Ecology, Evolution, Behavior and Systematics, Alphaproteobacteria, 030304 developmental biology, 0303 health sciences, 030306 microbiology, Phylum, respiratory system, bacterial infections and mycoses, biology.organism_classification, Ferrosoferric Oxide, Evolutionary biology, Magnetosomes, Proteobacteria, Magnetofossil
Abstract: Magnetotactic bacteria (MTB) are diverse prokaryotes that produce magnetic nanocrystals within intracellular membranes (magnetosomes). Here, we present a large-scale analysis of diversity and magnetosome biomineralization in modern magnetotactic cocci, which are the most abundant MTB morphotypes in nature. Nineteen novel magnetotactic cocci species are identified phylogenetically and structurally at the single-cell level. Phylogenetic analysis demonstrates that the cocci cluster into an independent branch from other Alphaproteobacteria MTB, that is, within the Etaproteobacteria class in the Proteobacteria phylum. Statistical analysis reveals species-specific biomineralization of magnetosomal magnetite morphologies. This further confirms that magnetosome biomineralization is controlled strictly by the MTB cell and differs among species or strains. The post-mortem remains of MTB are often preserved as magnetofossils within sediments or sedimentary rocks, yet paleobiological and geological interpretation of their fossil record remains challenging. Our results indicate that magnetofossil morphology could be a promising proxy for retrieving paleobiological information about ancient MTB.
Published: 2020

25. Formation of a Single‐Crystal Aluminum‐Based MOF Nanowire with Graphene Oxide Nanoscrolls as Structure‐Directing Agents

Author: Damien Aureau, Nicolas Menguy, Anusha Lalitha, Saad Sene, Christian Serre, Lucie Rivier, Imène Esteve, Nathalie Steunou, Mathieu Fregnaux, Guillaume Maurin, Naseem A. Ramsahye, Mégane Muschi, Clémence Sicard, Sabine Devautour-Vinot, Institut des Matériaux Poreux de Paris (IMAP ), Département de Chimie - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC), Institut Lavoisier de Versailles (ILV), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Institut des Matériaux Poreux de Paris (IMAP UMR8004 FRE2000), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS), Institut de minéralogie et de physique des milieux condensés (IMPMC), Université Pierre et Marie Curie - Paris 6 (UPMC)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), 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), and Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, Nanostructure, Oxide, Nanowire, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Catalysis, law.invention, chemistry.chemical_compound, X-ray photoelectron spectroscopy, law, [CHIM]Chemical Sciences, [CHIM.COOR]Chemical Sciences/Coordination chemistry, ComputingMilieux_MISCELLANEOUS, 010405 organic chemistry, Graphene, [CHIM.MATE]Chemical Sciences/Material chemistry, General Chemistry, General Medicine, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Chemical engineering, Electron diffraction, chemistry, Self-assembly, 0210 nano-technology, Single crystal
Abstract: International audience; Here we propose an innovative strategy to synthesize single-crystal nanowires (NWs) of the Al 3+ dicarboxylate MIL-69(Al) MOF by using graphene oxide nanoscrolls as structure directing agents. MIL-69(Al) NWs with an average diameter of 70 ± 20 nm and lengths up to 2 m were found to preferentially grow along the [001] crystallographic direction. Advanced characterization tools (electron diffraction, TEM, STEM-HAADF, SEM, XPS) and molecular modelling revealed the mechanism of formation of MIL-69(Al) NWs involving size-confinement and templating effects. The formation of MIL-69(Al) seeds and the self-scroll of GO sheets followed by the anisotropic growth of MIL-69(Al) crystals are mediated by specific GO sheets/MOF interactions. This study delivers an unprecedented approach to control the design of 1D MOF nanostructures and superstructures.
Published: 2020

26. Lake Pavin is a microbial mineralization oasis

Author: Christopher Lefevre, Nicolas Menguy, Karim Benzerara, Vincent Busigny, Camille Mangin, Neha Mehta, Cytnhia Travert, Romain Bolzoni, Cécile Bidaud, François Mathon, Didier Jézéquel, Eric Viollier, Fériel Skouri-Panet, Elodie Duprat, and Caroline Monteil
Published: 2022

27. Identification of sulfate‐reducing magnetotactic bacteria via a group‐specific 16S rDNA primer and correlative fluorescence and electron microscopy: Strategy for culture‐independent study

Author: Jinhua Li, Peiyu Liu, Nicolas Menguy, Karim Benzerara, Jinling Bai, Xiang Zhao, Eric Leroy, Chaoqun Zhang, Heng Zhang, Jiawei Liu, Rongrong Zhang, Kelei Zhu, Andrew P. Roberts, Yongxin Pan, Chinese Academy of Sciences [Beijing] (CAS), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), 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), Northeastern University [Shenyang], Institut de Chimie et des Matériaux Paris-Est (ICMPE), Institut de Chimie du CNRS (INC)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Informatique Paris Descartes (LIPADE - EA 2517), Université Paris Descartes - Paris 5 (UPD5), Department of Chemistry, Institute of Geology and Geophysics [Beijing] (IGG), and France-China Biomineralization and Nano-structures Laboratory
Subjects: Sulfates, Microbiology, DNA, Ribosomal, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Ferrosoferric Oxide, Lakes, Microscopy, Electron, RNA, Ribosomal, 16S, Desulfovibrio, Magnetosomes, Ecology, Evolution, Behavior and Systematics, Phylogeny, In Situ Hybridization, Fluorescence, [SDU.STU.MI]Sciences of the Universe [physics]/Earth Sciences/Mineralogy
Abstract: Magnetotactic bacteria (MTB) biomineralize intracellular magnetic nanocrystals and swim along geomagnetic field lines. While few axenic MTB cultures exist, living cells can be separated magnetically from natural environments for analysis. The bacterial universal 27F/1492R primer pair has been used widely to amplify nearly full-length 16S rRNA genes and to provide phylogenetic portraits of MTB communities. However, incomplete coverage and amplification biases inevitably prevent detection of some phylogenetically specific or non-abundant MTB. Here, we propose a new formulation of the upstream 390F primer that we combined with the downstream 1492R primer to specifically amplify 1100-bp 16S rRNA gene sequences of sulfate-reducing MTB in freshwater sediments from Lake Weiyanghu, Xi'an, northwestern China. With correlative fluorescence in situ hybridization and scanning/transmission electron microscopy, three novel MTB strains (WYHR-2, WYHR-3 and WYHR-4) from the Desulfobacterota phylum were identified phylogenetically and structurally at the single-cell level. Strain WYHR-2 produces bullet-shaped magnetosome magnetite, while the other two strains produce both cubic/prismatic greigite and bullet-shaped magnetite. Our results expand knowledge of bacterial diversity and magnetosome biomineralization of sulfate-reducing MTB. We also propose a general strategy for identifying and characterizing uncultured MTB from natural environments.
Published: 2022

28. ISME Journal

Author: Long Tian, Christopher T. Lefèvre, Austin Reed, Sophie LeBlanc, Haijie Liu, Caroline L. Monteil, Boris A. Vinatzer, Parul Sharma, Noam Eckshtain-Levi, Shu Yang, Nicolas Menguy, Kevin Failor, Marco E. Mechan Llontop, Liangcheng Du, Virginia Tech [Blacksburg], Michigan State University System, Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), University of Nebraska–Lincoln, University of Nebraska System, Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), and University of Nebraska [Lincoln]
Subjects: 010504 meteorology & atmospheric sciences, Mutant, Peptide, 01 natural sciences, Microbiology, Bacterial cell structure, 03 medical and health sciences, Polyketide synthase, Bacterial genetics, Ecology, Evolution, Behavior and Systematics, 030304 developmental biology, 0105 earth and related environmental sciences, 2. Zero hunger, chemistry.chemical_classification, 0303 health sciences, biology, Ribosomal RNA, Biogeochemistry, biology.organism_classification, Biochemistry, chemistry, [SDE]Environmental Sciences, biology.protein, Ice nucleus, Ultracentrifuge, Bacteria
Abstract: Earth's radiation budget and frequency and intensity of precipitation are influenced by aerosols with ice nucleation activity (INA), i.e., particles that catalyze the formation of ice. Some bacteria, fungi, and pollen are among the most efficient ice nucleators but the molecular basis of INA is poorly understood in most of them. Lysinibacillus parviboronicapiens (Lp) was previously identified as the first Gram-positive bacterium with INA. INA of Lp is associated with a secreted, nanometer-sized, non-proteinaceous macromolecule or particle. Here a combination of comparative genomics, transcriptomics, and a mutant screen showed that INA in Lp depends on a type I iterative polyketide synthase and a non-ribosomal peptide synthetase (PKS-NRPS). Differential filtration in combination with gradient ultracentrifugation revealed that the product of the PKS-NRPS is associated with secreted particles of a density typical of extracellular vesicles and electron microscopy showed that these particles consist in "pearl chain"-like structures not resembling any other known bacterial structures. These findings expand our knowledge of biological INA, may be a model for INA in other organisms for which the molecular basis of INA is unknown, and present another step towards unraveling the role of microbes in atmospheric processes. National Science FoundationNational Science Foundation (NSF) [IOS-1754721]; Virginia Agricultural Experiment Station; Hatch Program of the National Institute of Food and Agriculture, US Department of Agriculture Published version This study was supported by the National Science Foundation (IOS-1754721). Funding to Boris A. Vinatzer was also provided in part by the Virginia Agricultural Experiment Station and the Hatch Program of the National Institute of Food and Agriculture, US Department of Agriculture. We would like to thank Kate Costello, Nakysa Kheirandish, Michelle Zambrano, and Nnanna Onyekaba for help with the droplet freezing assays.
Published: 2021

29. Low Velocity Zones in the Martian Upper Mantle Highlighted by Sound Velocity Measurements

Author: Nicolas Wehr, N. C. Siersch, Yoshio Kono, James Badro, Steeve Gréaux, Hideharu Kuwahara, Daniele Antonangeli, Yuji Higo, Nicolas Menguy, Nozomi Kondo, Attilio Rivoldini, Fang Xu, Ana-Catalina Plesa, Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), and Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Martian, Upper Mantle, geography, geography.geographical_feature_category, 010504 meteorology & atmospheric sciences, Mars, Low Velocity Zones, [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph], Geophysics, 010502 geochemistry & geophysics, 01 natural sciences, Sound Velocity Measurements, [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, General Earth and Planetary Sciences, ComputingMilieux_MISCELLANEOUS, Sound (geography), Geology, InSight, [SDU.STU.MI]Sciences of the Universe [physics]/Earth Sciences/Mineralogy, 0105 earth and related environmental sciences
Abstract: International audience
Published: 2021

30. Comparative Cr and Mn speciation across a shore-to-reef gradient in lagoon sediments downstream of Cr-rich Ferralsols upon ultramafic rocks in New Caledonia

Author: Benjamin Moreton, Pauline Merrot, Jessica Brest, Farid Juillot, Guillaume Morin, Isabelle Kieffer, Jean-Michel Fernandez, Olivier Radakovitch, Eric Viollier, Pierre Le Pape, Nicolas Menguy, Pierre Lefebvre, Minéralogie Environnementale [IMPMC] (IMPMC_MINENV), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France, Institut de Physique du Globe de Paris (IPGP (UMR_7154)), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), and Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)
Subjects: Chromium, Goethite, Speciation, Geochemistry, Weathering, 010501 environmental sciences, 010502 geochemistry & geophysics, 01 natural sciences, Sediments, Geochemistry and Petrology, Ultramafic rock, Reef, 0105 earth and related environmental sciences, geography, Manganese, geography.geographical_feature_category, Lagoon, Diagenesis, visual_art, [SDE]Environmental Sciences, visual_art.visual_art_medium, Environmental science, Economic Geology, Sedimentary rock, Chromite, Clay minerals
Abstract: International audience; Ferralsols upon ultramafic rocks are among the most Cr-enriched soils at the Earth surface. Weathering and erosion of these soils represents a major source of Cr for coastal sediments downstream of ultramafic settings. Although Cr mainly occurs as Cr(III)-bearing chromite and Fe-(hydr)oxides in Ferralsols upon ultramafic rocks, several evidences of oxidized Cr(VI) in relation with Mn-oxides have been reported. Regarding the high solubility and toxicity of this latter Cr species, a thorough characterization of Cr and Mn crystal-chemistry in tropical sedimentary settings downstream of Ferralsols upon ultramafic rocks is needed to evaluate the potential threat towards the biodiversity of these coastal environments. In this study, we determined Cr and Mn speciation across a shore-to-reef gradient in lagoon sediments downstream of one of the largest lateritized ultramafic regolith in New Caledonia that contains up to 5 wt% Cr2O3. Chromium K-edge XANES data emphasized the absence of Cr (VI) and indicated a major hosting of Cr by chromite and clay minerals close to the shore, whereas Cr-bearing goethite dominated Cr speciation close to the reef. Manganese K-edge XANES data indicated a major hosting of Mn by clay minerals close to the shore, whereas Mn-carbonates dominated Mn speciation close to the reef. The lack of Mn-oxides detection was considered to explain the absence of Cr(VI) in the studied sediments. This result thus suggests that, despite their shallow character that can favor occasional re-oxidation of the top-layer sediments upon re-suspension events, lagoon sedimentary settings downstream of Cr-rich Ferralsols upon ultramafic rocks appear rather favorable to Cr sequestration as the less mobile and less toxic Cr(III) form. However, the reverse trends observed from the shore to the reef between the chromite and goethite contributions to Cr speciation, as well as the decrease of the Cr/Ti ratio, suggest that a fraction of Cr could have been released towards the water column upon partial weathering of chromite to goethite during sediments transport across the shore-to-reef gradient. This latter point emphasizes the potential hazard that could still represent Cr for the exceptional biodiversity of tropical lagoon ecosystems downstream of Cr-rich Ferralsols, despite the absence of detectable Cr(VI). It thus calls for further studies aimed at better evaluating the stability of Cr(III)-bearing mineral phases upon early diagenesis in these shallow sedimentary settings.
Published: 2021

31. Metal–Organic Framework Based 1D Nanostructures and Their Superstructures: Synthesis, Microstructure, and Properties

Author: Subharanjan Biswas, Clémence Sicard, Eddy Dumas, Nicolas Menguy, Ali Saad, Effrosyni Gkaniatsou, Nathalie Steunou, Institut Lavoisier de Versailles (ILV), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), and Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Nanostructure, Materials science, General Chemical Engineering, Metal organic frameworks, Nanotechnology, 02 engineering and technology, General Chemistry, Superstructures, 010402 general chemistry, 021001 nanoscience & nanotechnology, Microstructure, 01 natural sciences, 0104 chemical sciences, Nanostructures, Materials Chemistry, Genetics, [CHIM]Chemical Sciences, Metal-organic framework, 0210 nano-technology, Crystallization
Abstract: International audience; Owing to their high and tunable porosity as well as great chemical diversity, metal–organic frameworks (MOFs) have shown great promise over the past 20 years for a wide range of applications, including gas storage/separation, catalysis, and biomedicine. To date, MOF nanoparticles (NPs) have mostly been obtained as polycrystalline powders or spherical nanocrystals while anisotropic MOFs nanocrystals have been less explored and are of interest in the fields of catalysis, sensing, and electronics. One of the main challenges for the practical application of MOFs is thus to control the crystal size, morphology, and multiscale porosity of these materials while developing adequate shaping strategies. In this review, we cover recent advances in the different synthetic strategies of one-dimensional (1D) MOF nanocrystals as well as hierarchical porous superstructures based on tubular MOFs. We describe the architectures based on MOFs nanotubes (NTs), nanowires (NWs), and nanorods (NRs). Our discussion is focused on the synthetic approaches that drive the structure, crystallinity, size, and morphology of these hierarchical porous hybrid materials. Finally, their potential for different applications is presented.
Published: 2021

32. Diverse Intracellular Inclusion Types Within Magnetotactic Bacteria: Implications for Biogeochemical Cycling in Aquatic Environments

Author: Xiang Zhao, Andrew P. Roberts, Yan Liu, Jinhua Li, Nicolas Menguy, Yongxin Pan, Alima Tamaxia, Peiyu Liu, Heng Zhang, and Jian Wang
Subjects: Atmospheric Science, Biogeochemical cycle, Ecology, Magnetotactic bacteria, Aquatic ecosystem, Paleontology, Soil Science, Forestry, Aquatic Science, Biology, Environmental chemistry, Inclusion (mineral), Intracellular, Water Science and Technology, Biomineralization
Published: 2021

33. Ice nucleation in a Gram-positive bacterium isolated from precipitation depends on a polyketide synthase and non-ribosomal peptide synthetase

Author: Kevin C, Failor, Haijie, Liu, Marco E Mechan, Llontop, Sophie, LeBlanc, Noam, Eckshtain-Levi, Parul, Sharma, Austin, Reed, Shu, Yang, Long, Tian, Christopher T, Lefevre, Nicolas, Menguy, Liangcheng, Du, Caroline L, Monteil, and Boris A, Vinatzer
Subjects: Ice, Fungi, Peptide Synthases, Polyketide Synthases
Abstract: Earth's radiation budget and frequency and intensity of precipitation are influenced by aerosols with ice nucleation activity (INA), i.e., particles that catalyze the formation of ice. Some bacteria, fungi, and pollen are among the most efficient ice nucleators but the molecular basis of INA is poorly understood in most of them. Lysinibacillus parviboronicapiens (Lp) was previously identified as the first Gram-positive bacterium with INA. INA of Lp is associated with a secreted, nanometer-sized, non-proteinaceous macromolecule or particle. Here a combination of comparative genomics, transcriptomics, and a mutant screen showed that INA in Lp depends on a type I iterative polyketide synthase and a non-ribosomal peptide synthetase (PKS-NRPS). Differential filtration in combination with gradient ultracentrifugation revealed that the product of the PKS-NRPS is associated with secreted particles of a density typical of extracellular vesicles and electron microscopy showed that these particles consist in "pearl chain"-like structures not resembling any other known bacterial structures. These findings expand our knowledge of biological INA, may be a model for INA in other organisms for which the molecular basis of INA is unknown, and present another step towards unraveling the role of microbes in atmospheric processes.
Published: 2021

34. Competitive Seeded Growth: An Original Tool to Investigate Anisotropic Gold Nanoparticle Growth Mechanism

Author: Z. Cansu Canbek Ozdil, Fabienne Testard, Olivier Spalla, Nicolas Menguy, Laboratoire Interdisciplinaire sur l'Organisation Nanométrique et Supramoléculaire (LIONS), Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M) (NIMBE UMR 3685), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), CNRS Grant FR3507, Région Ile de France DIM C'NanoIdF, ANR-11-BS10-0006,MIGRANI,MIcrofluidique pour GRaines d'ANIsotropie(2011), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut Rayonnement Matière de Saclay (IRAMIS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)
Subjects: Materials science, Initial Seed, Scattering, food and beverages, Nanoparticle, [CHIM.MATE]Chemical Sciences/Material chemistry, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Mechanism (engineering), General Energy, Chemical physics, Seeding, Physical and Theoretical Chemistry, 0210 nano-technology, Spectroscopy, Anisotropy
Abstract: International audience; The influence of the initial seed structure on final nanoparticle geometry has been investigated by an original “competitive approach” using small-angle X-ray scattering, UV–vis spectroscopy, and transmission electronmicroscopy analysis. Herein, by using the seed-mediated gold nanoparticle growth, seeds with different sizes and crystalline structures were synthesized and injected into the same growth media. The seeds were chosen because of their different growth evolution into two different morphologies. Cetyltrimethylammonium bromide-coated single-crystalline seeds grow into rodlike shapes, whereas citrate-coated multicrystalline seeds mainly grow into wheat-shape polycrystalline particles with small elongation called nanobeans in coexistence with a large quantity of spheres. When seeds are added into the same growth media for competition, a mixture of different morphologies is obtained. By controlling the number of added competing seeds in the solution, it was found that the multicrystalline seeds have a higher growth rate than the single-crystalline seeds. This has direct impact on the final distribution of the size and morphology of the nanoparticles. The consequence is a large tendency toward nanobean and sphere structure formation even when a small number of multitwinned seeds is added in the solution. This method demonstrates the importance of the nature of defects hidden in the initial seed and proves that these defaults are inherited to the final nanocrystal throughout the growth stage from the beginning of the growth. This competitive seeded growth approach is an easy way to identify the influence of seed morphologies in the synthetic pathway of nanoparticle formation.
Published: 2019

35. Bio-inspired hydrophobicity promotes CO2 reduction on a Cu surface

Author: David W. Wakerley, Sarah Lamaison, Marc Fontecave, François Ozanam, Philippe Marcus, Nicolas Menguy, Victor Mougel, Dimitri Mercier, Chaire Chimie des processus biologiques, Laboratoire de Chimie des Processus Biologiques (LCPB), Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique de la matière condensée (LPMC), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche de Chimie Paris (IRCP), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Ministère de la Culture (MC), Collège de France - Chaire Chimie des processus biologiques, Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Ministère de la Culture (MC)
Subjects: chemistry.chemical_classification, Aqueous solution, Mechanical Engineering, [CHIM.MATE]Chemical Sciences/Material chemistry, 02 engineering and technology, General Chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Electrochemistry, Heterogeneous catalysis, Electrocatalyst, 01 natural sciences, 0104 chemical sciences, Catalysis, Hydrocarbon, chemistry, Chemical engineering, Mechanics of Materials, General Materials Science, Wetting, [CHIM.OTHE]Chemical Sciences/Other, 0210 nano-technology, Selectivity
Abstract: The aqueous electrocatalytic reduction of CO2 into alcohol and hydrocarbon fuels presents a sustainable route towards energy-rich chemical feedstocks. Cu is the only material able to catalyse the substantial formation of multicarbon products (C2/C3), but competing proton reduction to hydrogen is an ever-present drain on selectivity. Here, a superhydrophobic surface was generated by 1-octadecanethiol treatment of hierarchically structured Cu dendrites, inspired by the structure of gas-trapping cuticles on subaquatic spiders. The hydrophobic electrode attained a 56% Faradaic efficiency for ethylene and 17% for ethanol production at neutral pH, compared to 9% and 4% on a hydrophilic, wettable equivalent. These observations are assigned to trapped gases at the hydrophobic Cu surface, which increase the concentration of CO2 at the electrode–solution interface and consequently increase CO2 reduction selectivity. Hydrophobicity is thus proposed as a governing factor in CO2 reduction selectivity and can help explain trends seen on previously reported electrocatalysts. Aqueous electrocatalytic reduction of CO2 into alcohol and hydrocarbon fuels is a sustainable route towards energy-rich chemical feedstocks. A superhydrophobic surface of hierarchically structured Cu dendrites exhibits a significant increase in CO2 reduction selectivity.
Published: 2019

36. Covalent and Selective Grafting of Polyethylene Glycol Brushes at the Surface of ZIF-8 for the Processing of Membranes for Pervaporation

Author: Thomas Berthelot, Elena Bellido, Florent Carn, Patricia Horcajada, Rocio Semino, Nicolas Menguy, Maria E. Dmitrenko, Guillaume Maurin, Denis Roizard, Sérgio R. Tavares, Marvin Benzaqui, Christian Serre, Nathalie Steunou, Anastasia V. Penkova, Mónica Giménez-Marqués, Anna I. Kuzminova, Institut Lavoisier de Versailles (ILV), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut des Matériaux Poreux de Paris (IMAP ), Département de Chimie - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Matière et Systèmes Complexes (MSC), Université Paris Diderot - Paris 7 (UPD7)-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), Instituto IMDEA Energía, Laboratoire Innovation en Chimie des Surfaces et NanoSciences (LICSEN UMR 3685), Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M) (NIMBE UMR 3685), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Service de Physique et de Chimie des Surfaces et Interfaces (SPCSI), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Saint Petersburg University (SPBU), Laboratoire Réactions et Génie des Procédés (LRGP), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), ANR-10-LABX-0035,Nano-Saclay,Paris-Saclay multidisciplinary Nano-Lab(2010), European Project: 608490,EC:FP7:ENERGY,FP7-ENERGY-2013-1,M4CO2(2014), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Matière et Systèmes Complexes (MSC (UMR_7057)), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), Laboratoire Innovation en Chimie des Surfaces et NanoSciences (LICSEN), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Centre National de la Recherche Scientifique (CNRS)-Université de Lorraine (UL), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS), Institut des Matériaux Poreux de Paris (IMAP UMR8004 FRE2000), École normale supérieure - Paris (ENS Paris)-École normale supérieure - Paris (ENS Paris)-ESPCI ParisTech-Centre National de la Recherche Scientifique (CNRS), Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Institut de recherche pour le développement [IRD] : UR206-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC), Instituto IMDEA Energy, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and ANR: NanoSaclay,ANR-10-LABX-0035
Subjects: Vinyl alcohol, Materials science, Poly(vinyl alcohol), General Chemical Engineering, Nanoparticle, 02 engineering and technology, Polyethylene glycol, 010402 general chemistry, 01 natural sciences, chemistry.chemical_compound, Pervaporation, Surface modification, Dynamic light scattering, Environmental Chemistry, Membranes, Renewable Energy, Sustainability and the Environment, technology, industry, and agriculture, [CHIM.MATE]Chemical Sciences/Material chemistry, General Chemistry, 021001 nanoscience & nanotechnology, MOFs, 0104 chemical sciences, Membrane, chemistry, Chemical engineering, Membranes, MOFs, Pervaporation, Poly(vinyl alcohol), Surface modification, 0210 nano-technology, Zeolitic imidazolate framework
Abstract: International audience; The so-called Graftfast reaction in water and at room temperature (RT) was applied to graft polyethylene glycol (PEG) at the surface of the microporous zeolitic imidazolate framework ZIF-8 nanoparticles (NPs) using acrylPEG of different chain lengths (480 Da and 5 kDa). In comparison to non-modified ZIF-8 NPs, both chemical and colloidal stabilities of PEGylated ZIF-8 NPs are significantly enhanced in water. A series of colloidal complex fluids by mixing PEG grafted ZIF-8 (i. e. PEG-g-ZIF-8) NPs with different amounts of polyvinylalcohol (PVA) was prepared and characterized by advanced characterization tools such as dynamic light scattering (DLS) and small-angle X-ray scattering (SAXS) thereby showing their long-term colloidal stability. Finally, dense and supported mixed matrix membranes were cast from PEG-g-ZIF-8/PVA solutions and have shown high performance in isopropanol (IPA) dehydration by pervaporation. The permeation flux of the supported MMM (i. e. 0.091 kg/(m$^2$h) is eleven times higher than that of the pure PVA membrane and these MMMs present a high separation factor (i. e. 7326). These transport properties are presumably due to the molecular sieving effects induced by ZIF-8 and the good interfacial properties of the membrane. The computational exploration of the ZIF-8/PVA and PEG/PVA interfaces provides a microscopic scale explanation for the enhanced compatibility of PVA with the PEGylated MOF when compared to that for the composite based on the bare ZIF-8 as a filler.
Published: 2019

37. Biogeochemical niche of phosphorus sequestrating magnetotactic bacteria in Lake Pavin, a freshwater feruginous environment

Author: Caroline L. Monteil, Elodie Duprat, Cécile C. Bidaud, Christopher T. Lefèvre, Fériel Skouri-Panet, Didier Jézéquel, Nicolas Menguy, Eric Viollier, Karim Benzerara, Vincent Busigny, and Cynthia Travert
Subjects: Water column, Magnetotactic bacteria, Chemistry, Environmental chemistry, Population structure, Intracellular
Abstract: Phosphorus (P) is essential to life but a limiting nutrient in many ecosystems. Understanding the role of microorganisms in P cycling, especially the processes of P uptake and storage, is a major environmental issue. Only few models are known to highly sequestrate phosphorus and mostly in marine environments. We thus need to improve our knowledge about other model of sequestration and especially in freshwater environments.Freshwater magnetotactic bacteria (MTB) affiliated to the Magnetococcaceae family have been identified within the water column of Lake Pavin in France [3]. Similarly, to the marine Thiomarguarita and Beggiatoa [1, 2], they accumulate intracellular polyphosphates (PolyP) to a uniquely high extent, up to 90% of their cell volume. In contradiction with the marine Thiomarguarita and Beggiatoa, the Magnetococcaceae accumulate PolyP in anoxic conditions. They represent the major population of MTB and are located right under the oxic-anoxic interface in a zone of strong chemical and redox gradients. These gradients allow the study of the impact of varying chemical conditions on microbial physiology.We aim at characterizing Magnetococcaceae distribution as a function of depth and therefore of different chemical parameters, but also at determining the drivers of PolyP accumulation. Here, we combine a variety of methods to analyse these MTB and their potential appartenance to a specific ecological niche in the water column. We measured the physico-chemical parameters of the water column (O2, pH, redox, conductivity, FDOM, turbidity, etc.). We used a new sampling system that allowed us to reach a better spatial resolution [4], from 1 m to 20 cm. We were therefore able to better estimate the impact of the chemical parameters on the MTB. We then sampled the water to measure the geochemical parameters using ICP-OES and to characterize MTB via optical and electronic microscopy. Optical microscopy helped identify the main populations of MTB and their concentrations, while electronic microscopy permitted the characterization of the different magnetosome organisation and PolyP accumulation capacities. Multivariate statistics were finally performed on all data.Multivariate statistics identified several parameters positively and significantly correlated to the Magnetococcaceae. These parameters are different from the ones correlated to other MTB of the water column. We therefore show that the Magnetococcaceae live into a specific niche with specific biogeochemical parameters. These correlated parameters include dissolved lithium concentration, mass percentage of nitrogen, magnesium and particulate P. Phosporus and magnesium are linked to the formation of PolyP, lithium represent a cofactor for phosphate transport [5] and nitrogen might be linked to nitrate transportation by the MTB [6].Genomic analyses will be done in the future to allow further comprehension on molecular mecanisms and PolyP formation. [1] Brock J, Schulz-Vogt HN. (2011) ISME Journal 5, 497-506. [2] Mubmann M et al. (2007) PLoS Biology 5(9), e230. [3] Rivas-Lamelo S et al. (2017) Geochem. Persp. Let. 5, 35–41. [4] Busigny et al., submitted to Environmental Microbiology. [5] Jakobsson E et al. (2017) J. Membr. Biol. 250,587-604. [6] Li et al. (2020) Geophys. Res. Biogeosciences.
Published: 2021

38. Mass collection of magnetotactic bacteria from the permanently stratified ferruginous Lake Pavin, France

Author: Karim Benzerara, Didier Jézéquel, Nicolas Menguy, François P. Mathon, Christopher T. Lefèvre, Jean‐Jacques Bourrand, Eric Viollier, Cécile C. Bidaud, Caroline L. Monteil, Gérard Bardoux, Elodie Duprat, Vincent Busigny, Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Centre Alpin de Recherche sur les Réseaux Trophiques et Ecosystèmes Limniques (CARRTEL), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), French National Research Agency (ANR)SIGMAG: ANR-18-CE31-0003PHOSTORE: ANR-19-CE01-0005CNRS: 'DEFI Instrumentation aux limites' (MAGNETOTRAP project)'Programme National Ecosphere Continentale et Cotiere (EC2CO)' (BACCARAT2 project)13068Frontieres de l'Innovation en Recherche et Education (FIRE) PhD program from the Centre de Recherches Interdisciplinaires (CRI), Institut de Physique du Globe de Paris (IPGP (UMR_7154)), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), ANR-18-CE31-0003,SIGMAG,SIGNATURE DES MAGNETITES PRODUITES PAR LES BACTERIES MAGNETOTACTIQUES : PERSPECTIVES CHIMIQUES ET ISOTOPIQUES(2018), and ANR-19-CE01-0005,PHOSTORE,Piégeage du phosphore : contribution des bactéries magnétotactiques dans les zones de transition oxique-anoxique(2019)
Subjects: Magnetotactic bacteria, Earth science, Microorganism, Magnetosome, Biology, Microbiology, 03 medical and health sciences, Water column, Crater lake, Ecology, Evolution, Behavior and Systematics, Nansen bottle, Ecosystem, Phylogeny, 030304 developmental biology, 0303 health sciences, Bacteria, 030306 microbiology, Aquatic ecosystem, Sediment, 15. Life on land, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Lakes, 13. Climate action, Magnetosomes, Metagenomics, [SDE.BE]Environmental Sciences/Biodiversity and Ecology
Abstract: Obtaining high biomass yields of specific microorganisms for culture-independent approaches is a challenge faced by scientists studying organisms recalcitrant to laboratory conditions and culture. This difficulty is highly decreased when studying magnetotactic bacteria (MTB) since their unique behavior allows their enrichment and purification from other microorganisms present in aquatic environments. Here, we use Lake Pavin, a permanently stratified lake in the French Massif Central, as a natural laboratory to optimize collection and concentration of MTB that thrive in the water column and sediments. A method is presented to separate MTB from highly abundant abiotic magnetic particles in the sediment of this crater lake. For the water column, different sampling approaches are compared such as in situ collection using a Niskin bottle and online pumping. By monitoring several physicochemical parameters of the water column, we identify the ecological niche where MTB live. Then, by focusing our sampling at the peak of MTB abundance, we show that the online pumping system is the most efficient for fast recovering of large volumes of water at a high spatial resolution, which is necessary considering the sharp physicochemical gradients observed in the water column. Taking advantage of aerotactic and magnetic MTB properties, we present an efficient method for MTB concentration from large volumes of water. Our methodology represents a first step for further multidisciplinary investigations of the diversity, metagenomic and ecology of MTB populations in Lake Pavin and elsewhere, as well as chemical and isotopic analyses of their magnetosomes. This article is protected by copyright. All rights reserved.
Published: 2021

39. Diagenetic formation of uranium-silica polymers in lake sediments over 3,300 years

Author: Mathilde Zebracki, Pascale Louvat, Emmanuel Malet, Pierre Lefebvre, Didier Jézéquel, Pierre Le Pape, Alkiviadis Gourgiotis, John R. Bargar, Pascale Blanchart, Nicolas Menguy, Jean-Louis Reyss, Guillaume Morin, Pauline Merrot, Camille Baya, Charlotte Cazala, Pierre Sabatier, Jérôme Gaillardet, Arnaud Mangeret, Olivier Diez, Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), PSE-ENV/SEDRE/LELI, Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Environnements, Dynamiques et Territoires de la Montagne (EDYTEM), Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry]), Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), PSE-ENV/SEDRE/USDR, Centre Alpin de Recherche sur les Réseaux Trophiques et Ecosystèmes Limniques (CARRTEL), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Stanford Synchrotron Radiation Lightsource (SSRL SLAC), SLAC National Accelerator Laboratory (SLAC), Stanford University-Stanford University, Minéralogie Environnementale (MinEnv), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), United States Department of Energy (DOE)DE-AC02-76SF00515IPGP multidisciplinary program PARIParis-IdF Region SESAME Grant12015908IRSNLS 20942, ANR-18-IDEX-0001,Université de Paris,Université de Paris(2018), Service des déchets radioactifs et des transferts dans la géosphère (IRSN/PSE-ENV/SEDRE), Environnements, Dynamiques et Territoires de Montagne (EDYTEM), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Propriétés des amorphes, liquides et minéraux [IMPMC] (IMPMC_PALM), Laboratoire de recherche sur le devenir des pollutions de sites radioactifs (IRSN/PSE-ENV/SEDRE/LELI), Institut de Radioprotection et de Sûreté Nucléaire (IRSN)-Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Institut de Physique du Globe de Paris (IPGP (UMR_7154)), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Unité d'expertise des sites et des déchets radioactifs (IRSN/PSE-ENV/SEDRE/USDR), and IMPMC_Minéralogie Environnementale (IMPMC_MINENV)
Subjects: media_common.quotation_subject, lake sediments, chemistry.chemical_element, 010501 environmental sciences, 010502 geochemistry & geophysics, 01 natural sciences, uranium, Coffinite, Organic matter, 0105 earth and related environmental sciences, media_common, chemistry.chemical_classification, Multidisciplinary, Isotopes of uranium, Lability, Authigenic, Uranium, diagenetic aging, noncrystalline species, Diagenesis, Speciation, chemistry, 13. Climate action, Environmental chemistry, Physical Sciences, [SDE]Environmental Sciences, uranium isotopes
Abstract: The long-term fate of uranium-contaminated sediments, especially downstream former mining areas, is a widespread environmental challenge. Essential for their management is the proper understanding of uranium (U) immobilization mechanisms in reducing environments. In particular, the long-term behavior of noncrystalline U(IV) species and their possible evolution to more stable phases in subsurface conditions is poorly documented, which limits our ability to predict U long-term geochemical reactivity. Here, we report direct evidence for the evolution of U speciation over 3,300 y in naturally highly U-enriched sediments (350–760 µg ⋅ g(−1) U) from Lake Nègre (Mercantour Massif, Mediterranean Alps, France) by combining U isotopic data (δ(238)U and ((234)U/(238)U)) with U L(3)-edge X-ray absorption fine structure spectroscopy. Constant isotopic ratios over the entire sediment core indicate stable U sources and accumulation modes, allowing for determination of the impact of aging on U speciation. We demonstrate that, after sediment deposition, mononuclear U(IV) species associated with organic matter transformed into authigenic polymeric U(IV)–silica species that might have partially converted to a nanocrystalline coffinite (U(IV)SiO(4)·nH(2)O)-like phase. This diagenetic transformation occurred in less than 700 y and is consistent with the high silica availability of sediments in which diatoms are abundant. It also yields consistency with laboratory studies that proposed the formation of colloidal polynuclear U(IV)–silica species, as precursors for coffinite formation. However, the incomplete transformation observed here only slightly reduces the potential lability of U, which could have important implications to evaluate the long-term management of U-contaminated sediments and, by extension, of U-bearing wastes in silica-rich subsurface environments.
Published: 2021

40. Evolution of noncrystalline uranium in lake sediments over 3,300 years

Author: Mathilde Zebracki, Emmanuel Malet, Jean-Louis Reyss, Didier Jézéquel, Charlotte Cazala, Nicolas Menguy, Alkiviadis Gourgiotis, Pauline Merrot, John R. Bargar, Pierre Le Pape, Guillaume Morin, Pierre Lefebvre, Pascale Louvat, Pascale Blanchart, Pierre Sabatier, Camille Baya, Jérôme Gaillardet, Arnaud Mangeret, and Olivier Diez
Subjects: chemistry, Geochemistry, chemistry.chemical_element, Uranium, Geology
Published: 2021

41. Biomineralization of (Fe,Mn)-rich silicates in an oxic environment by oxygenic photosynthesizers

Author: Agnès Elmaleh, Purificación López-García, Maria Cristina Ciobanu, David Moreira, Miguel Iniesto, Karim Benzerara, Fériel Skouri-Panet, Rosaluz Tavera, Didier Jézéquel, and Nicolas Menguy
Subjects: Chemistry, Environmental chemistry, Biomineralization
Published: 2021

42. Massive Intracellular Remodeling of CuS Nanomaterials Produces Nontoxic Bioengineered Structures with Preserved Photothermal Potential

Author: Aurore Van de Walle, Ara Sargsian, Alberto Curcio, Nicolas Menguy, Ali Abou-Hassan, Ana Espinosa, Nathalie Luciani, Bella B. Manshian, Aida Serrano, Emilia Benassai, Claire Wilhelm, Stefaan J. Soenen, Matière et Systèmes Complexes (MSC (UMR_7057)), Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Laboratoire Physico-Chimie Curie [Institut Curie] (PCC), Institut Curie [Paris]-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), PHysicochimie des Electrolytes et Nanosystèmes InterfaciauX (PHENIX), Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), European Synchrotron Radiation Facility (ESRF), Instituto de Cerámica y Vidrio (ICV), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), Instituto IMDEA Nanociencia [Madrid], Instituto Imdea Nanociencia, Centro Nacional de Biotecnología [Madrid] (CNB-CSIC), Matière et Systèmes Complexes (MSC), Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), and Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPC)
Subjects: Technology, Chemistry, Multidisciplinary, COPPER, General Physics and Astronomy, Nanoparticle, 02 engineering and technology, [CHIM.THER]Chemical Sciences/Medicinal Chemistry, THERAPY, 01 natural sciences, biodegradation, TOXICITY, Nanomaterials, DISSOLUTION, General Materials Science, Chemistry, Physical, Chemistry, General Engineering, CuS nanoparticles, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, 3. Good health, Physical Sciences, Science & Technology - Other Topics, 0210 nano-technology, PROTEIN CORONA, Intracellular, magnetic nanoparticles, INTERPLAY, Biocompatibility, Materials Science, Materials Science, Multidisciplinary, Nanotechnology, Sulfides, 010402 general chemistry, INORGANIC NANOPARTICLES, biocompatibility, Viability assay, Nanoscience & Nanotechnology, Bioprocess, Science & Technology, photothermia, bioprocessing, IRON-OXIDE NANOPARTICLES, DEGRADATION, Photothermal therapy, Phototherapy, 0104 chemical sciences, Nanostructures, CELLS, Magnetic nanoparticles, Nanoparticles, biosynthesis, Copper
Abstract: Despite efforts in producing nanoparticles with tightly controlled designs and specific physicochemical properties, these can undergo massive nano-bio interactions and bioprocessing upon internalization into cells. These transformations can generate adverse biological outcomes and premature loss of functional efficacy. Hence, understanding the intracellular fate of nanoparticles is a necessary prerequisite for their introduction in medicine. Among nanomaterials devoted to theranostics is copper sulfide (CuS), which provides outstanding optical properties along with easy synthesis and low cost. Herein, we performed a long-term multiscale study on the bioprocessing of hollow CuS nanoparticles (CuS NPs) and rattle-like iron oxide nanoflowers@CuS core-shell hybrids (IONF@CuS NPs) when inside stem cells and cancer cells, cultured as spheroids. In the spheroids, both CuS NPs and IONF@CuS NPs are rapidly dismantled into smaller units (day 0 to 3), and hair-like nanostructures are generated (day 9 to 21). This bioprocessing triggers an adaptation of the cellular metabolism to the internalized metals without impacting cell viability, differentiation, or oxidative stress response. Throughout the remodeling, a loss of IONF-derived magnetism is observed, but, surprisingly, the CuS photothermal potential is preserved, as demonstrated by a full characterization of the photothermal conversion across the bioprocessing process. The maintained photothermal efficiency correlated well with synchrotron X-ray absorption spectroscopy measurements, evidencing a similar chemical phase for Cu but not for Fe over time. These findings evidence that the intracellular bioprocessing of CuS nanoparticles can reshape them into bioengineered nanostructures without reducing the photothermal function and therapeutic potential. ispartof: ACS NANO vol:15 issue:6 pages:9782-9795 ispartof: location:United States status: published
Published: 2021

43. Biomineralization of intracelllar amorphous calcium carbonates (ACC) by bacteria: molecular mechanisms, evolutionary history and environmental significance

Author: Karim Benzerara, Isabelle Callebaut, Romain Bolzoni, Christopher T. Lefèvre, Caroline L. Monteil, Elodie Duprat, Issa Diop, Purificación López-García, Sigrid Görgen, Geoffroy Gaschignard, Géradline Caumes, David Moreira, Corinne Cassier-Chauvat, Tristan Bitard-Feildel, Manuela Dezi, Fériel Skouri-Panet, Nicolas Menguy, and Franck Chauvat
Subjects: biology, Biochemistry, chemistry, chemistry.chemical_element, Calcium, biology.organism_classification, Bacteria, Amorphous solid, Biomineralization
Published: 2021

44. Experimental and theoretical evidence for oriented aggregate crystal growth of CoO in a polyol

Author: Surender K. Sharma, Rahamane Mohamed, B. Sitamtze Youmbi, Nicolas Menguy, S. Ammar-Merah, Mahamadou Seydou, Thomas Gaudisson, Florent Calvayrac, Interfaces, Traitements, Organisation et Dynamique des Systèmes (ITODYS (UMR_7086)), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Institut des Molécules et Matériaux du Mans (IMMM), Le Mans Université (UM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), and Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)
Subjects: Materials science, Intermolecular force, Ab initio, chemistry.chemical_element, Crystal growth, 02 engineering and technology, General Chemistry, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, 0104 chemical sciences, Crystal, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Crystallography, Adsorption, chemistry, Nanocrystal, Molecule, General Materials Science, 0210 nano-technology, Cobalt
Abstract: International audience; Monodispersed about 5 nm sized CoO crystals were prepared by forced hydrolysis of cobalt(II) acetate in diethyleneglycol (DEG) solvent. The adsorption of the solvent molecules on these primary nanocrystals caused their in-situ oriented aggregation resulting in the precipitation of textured submicrometer-sized polycrystals. X-ray diffraction, Infrared spectroscopy, Transmission Electron Microscopy and Thermogravimetry analyses coupled to ab-initio modeling were applied to understand the adsorption mechanism of the alcohol moieties and the role of the molecule-to-surface and molecule-to-molecule interactions in the crystal growth mechanism of these polycrystals. We showed that DEG moieties are mainly adsorbed at the top of the cobalt (100) surface atoms and the process does not involve the whole molecule but only one of its extreme oxygen atoms. As a consequence, adsorbed DEG molecules exhibit an extended configuration which is favorable to intermolecule hydrogen bonding from one covered nanocrystal to another. Interestingly, at high surface coverage, the energy required for DEG attachment to the crystal surface is found to be 18.6 kJ/mol per molecule, while that required for hydrogen bonding between a bearing molecule and a neighbor one is found to be 36,4 kJ/mol per molecule, meaning that the collective departure of an assembly of DEG from the surface of CoO nanocrystals is therodynamically easier, leading thus to the observed final morphology.
Published: 2021

45. Biomineralization and Magnetism of Uncultured Magnetotactic Coccus Strain THC‐1 With Non‐chained Magnetosomal Magnetite Nanoparticles

Author: Andrew P. Roberts, Eric Leroy, Jinhua Li, Nicolas Menguy, Yongxin Pan, and Peiyu Liu
Subjects: Materials science, 010504 meteorology & atmospheric sciences, biology, Magnetotactic bacteria, Strain (chemistry), Magnetism, Coccus (insect), 010502 geochemistry & geophysics, biology.organism_classification, 01 natural sciences, Magnetite Nanoparticles, Geophysics, Chemical engineering, Space and Planetary Science, Geochemistry and Petrology, Earth and Planetary Sciences (miscellaneous), 0105 earth and related environmental sciences, Biomineralization
Published: 2020

46. Chapter 9: Electron microscopy applied to the study of nucleation and crystallisation in glasses

Author: Olivier Dargaud, Laurent Cormier, and Nicolas Menguy
Subjects: Materials science, Chemical engineering, law, Nucleation, Crystallization, Electron microscope, law.invention
Published: 2020

47. Chemical Heterogeneities within the Disordered Mineral domains of Aragonite Platelets in Nacre from the European Abalone Haliotis tuberculata

Author: Sylvain Huchette, Axel Gansmüller, Nadine Nassif, Guillaume Laurent, Widad Ajili, Nicolas Menguy, Stéphanie Auzoux-Bordenave, Thierry Azaïs, Laboratoire de Chimie de la Matière Condensée de Paris (LCMCP), Collège de France (CdF (institution))-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Cristallographie, Résonance Magnétique et Modélisations (CRM2), Centre National de la Recherche Scientifique (CNRS)-Université de Lorraine (UL), Scea France Haliotis, Biologie des Organismes et Ecosystèmes Aquatiques (BOREA), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA), Spectroscopie, Modélisation, Interfaces pour L'Environnement et la Santé (LCMCP-SMiLES), Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Sorbonne Université (SU)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU), Matériaux Hybrides et Procédés (LCMCP-MHP ), Matériaux Hybrides et Nanomatériaux (LCMCP-MHN), Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire de Chimie de la Matière Condensée de Paris (LCMCP), ANR-11-IDEX-0004,SUPER,Sorbonne Universités à Paris pour l'Enseignement et la Recherche(2011), and Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)
Subjects: food.ingredient, Abalone, 02 engineering and technology, engineering.material, 010402 general chemistry, 01 natural sciences, food, [CHIM.ANAL]Chemical Sciences/Analytical chemistry, [CHIM]Chemical Sciences, Haliotis, Physical and Theoretical Chemistry, ComputingMilieux_MISCELLANEOUS, Mineral, biology, Chemistry, Aragonite, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, biology.organism_classification, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, General Energy, Haliotis laevigata, Chemical engineering, engineering, 0210 nano-technology
Abstract: International audience; Since the observation in 2005 of a disordered mineral layer at the surface of aragonite platelets in abalone Haliotis laevigata nacre, the model of the organo–mineral interface in such biomineralized tissue has been challenged. As a direct interaction between the aragonite crystalline core and the organic matrix is no longer appropriate to describe such interface, a structural description of the disordered mineral domains at the atomic level is a key for a comprehensive view of nacre ultrastructure. Here, we use European abalone Haliotis tuberculata as a model to investigate aragonite nacre through high-resolution transmission electron microscopy (HR-TEM) and multinuclear solid state nuclear magnetic resonance (ssNMR). The presence of a disordered domain around aragonite crystals is shown through HR-TEM observations similarly to H. laevigata. The structure and the ionic composition of the disordered mineral environments of H. tuberculata nacre are investigated through 1H, 13C, 43Ca, and 23Na ssNMR. Interestingly, we demonstrate that the disordered mineral domains in nacre seem to be heterogeneous in terms of structure and chemical composition and do not match with amorphous calcium carbonate stricto sensu. At least three different carbonates species are evidenced, including CO32– and HCO3– present in the same mineral domain and closely associated with rigid H2O molecules. The local disorder around these ions is found to be inhomogeneous as some CO32– possess an aragonitic environment and are rather ordered (according to the position and line width of their 13C resonance) whereas, in opposition, the chemical environment around HCO3– is highly distributed. The analysis of potential cations as counterions revealed the presence of disordered Ca2+ and the presence of Na+ closely associated with HCO3–. On the basis of these structural data, we propose an atomic-level model for the disordered domains in abalone (H.tuberculata) nacre where the protonation level of carbonate ions, the proportion of sodium ions and the local disorder are increasing from the inner to the outer part of disordered domains. These results give an unprecedented structural view at the atomic scale of such disordered mineral domains in nacre aragonite tablets.
Published: 2020

48. Bullet‐Shaped Magnetite Biomineralization Within a Magnetotactic Deltaproteobacterium: Implications for Magnetofossil Identification

Author: Julie Bourgon, Eric Leroy, Hitesh Changela, Lin Gu, Yongxin Pan, Xin’an Yang, Jinhua Li, Nicolas Menguy, Xiang Zhao, Peiyu Liu, and Andrew P. Roberts
Subjects: 0303 health sciences, Atmospheric Science, Ecology, Magnetotactic bacteria, 030306 microbiology, Chemistry, Paleontology, Soil Science, Forestry, Nanotechnology, Aquatic Science, 03 medical and health sciences, chemistry.chemical_compound, Identification (biology), Magnetofossil, 030304 developmental biology, Water Science and Technology, Magnetite, Biomineralization
Published: 2020

49. Exchange-bias features in nanoceramics prepared by spark plasma sintering of exchange-biased nanopowders

Author: Nader Yaacoub, Giulia Franceschin, Sonia Perez Quiros, Jean-Marc Greneche, Silvana Mercone, Thomas Gaudisson, Frédéric Mazaleyrat, Souad Ammar, Nicolas Menguy, Institut des Molécules et Matériaux du Mans (IMMM), and Le Mans Université (UM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 010302 applied physics, [PHYS]Physics [physics], Materials science, Condensed matter physics, Sintering, Spark plasma sintering, 02 engineering and technology, General Chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, Nanocrystalline material, Atomic diffusion, Grain growth, Exchange bias, 0103 physical sciences, Materials Chemistry, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], 0210 nano-technology, Néel temperature, ComputingMilieux_MISCELLANEOUS, Solid solution
Abstract: Conventional methods for sintering magnetic biased granular solids are generally known to induce severe grain growth and coarsening, thus making any evidence of exchange bias (EB) hard to detect in the resulting consolidates. This work explores the possibility of preparing a hetero-nanoconsolidate starting from an exchange-biased nanopowder and using Spark Plasma Sintering (SPS), in order to overcome that microstructural limitation. It also investigates the capability of the resulting solid to establish EB. The nanopowder consists of an intimate nanocrystalline mixture of the antiferromagnetic NiO and ferrimagnetic CoFe2O4 phases. It exhibits a significant broadening of the hysteresis loop at room temperature when measured under field cooling (FC) conditions. X-ray diffraction coupled to high resolution transmission electron microscopy and 57Fe Mossbauer spectrometry shows that sintering induces a drastic atomic diffusion leading to the replacement of the starting NiO and CoFe2O4 phases by their Ni1−xCoxO and Co1−xNixFe2O4 solid solutions (x value close to 0.25). As a result, exchange-bias is hindered at 300 K but always expressed at lower temperatures, far below the Neel temperature of the new antiferromagnet. The maximum EB value for the ceramics is measured at 5 K and is calculated about 48 mT under a cooling magnetic field of 7 T. This value decreases when the temperature increases, but it remains different from zero up to 200 K.
Published: 2020

50. Juxtaposed membranes underpin cellular adhesion and display unilateral cell division of multicellular magnetotactic prokaryotes

Author: Xin-Xin Qian, Hugo Le Guenno, Claire-Lise Santini, Jinhua Li, Long-Fei Wu, Nicolas Menguy, Artemis Kosta, Wenyan Zhang, Jia Liu, Tian Xiao, Leon Espinosa, François Alberto, Yi-Ran Chen, Laboratoire de chimie bactérienne (LCB), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Institut de Microbiologie de la Méditerranée (IMM), 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), Chinese Academy of Sciences [Qingdao], Chinese Academy of Sciences [Beijing] (CAS), CAS Institute of Oceanology (IOCAS), This work was supported by a fundingfrom the Excellence Initiative of Aix-453Marseille University -A*Midex, a French 'Investissements d’Avenir' programme, by grants 45441330962 and 41506147 from NSFC, grant 2018YFC0309904 from National Key R&D 455Program of China, grant XDB06010203 from the Strategic Priority Research Program and 45625grants from CNRS for LIA-MagMC. The FISH-SEM experiments were performed at the 457IGGCAS, Beijing, China and were supported by a NSFC grant 41522402, ANR-11-IDEX-0001,Amidex,INITIATIVE D'EXCELLENCE AIX MARSEILLE UNIVERSITE(2011), and Aix Marseille Université (AMU)
Subjects: Cell division, [SDV]Life Sciences [q-bio], Motility, Biology, Microbiology, law.invention, Cell membrane, 03 medical and health sciences, Confocal microscopy, law, Cell Adhesion, medicine, 14. Life underwater, Cell adhesion, In Situ Hybridization, Fluorescence, Ecology, Evolution, Behavior and Systematics, ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, 0303 health sciences, 030306 microbiology, Magnetic Phenomena, Cell Membrane, Multicellular organism, Membrane, medicine.anatomical_structure, Prokaryotic Cells, Freeze substitution, Microscopy, Electron, Scanning, Biophysics, Cell Division
Abstract: International audience; Multicellular magnetotactic prokaryotes (MMPs) exhibit peculiar coordination of swimming along geomagnetic field lines. Approximately 40–80 cells assemble, with a helical geometry or axisymmetry, into spherical or ellipsoidal MMPs respectively. To contribute to a comprehensive understanding of bacterial multicellularity here we took multiple microscopic approaches to study the diversity, assembly, reproduction and motility of ellipsoidal MMPs. Using correlative fluorescence in situ hybridization and scanning electron microscopy analysis, we found an unexpected diversity in populations of ellipsoidal MMPs in the Mediterranean Sea. The high‐pressure freezing/freeze substitution fixation technique allowed us to show, for the first time, that cells adhere via juxtaposed membranes and are held together by a rimming lattice. Fluorescence confocal microscopy and ultrathin section images revealed not only the one‐layer hollow three‐dimensional architecture, but also periphery–core unilateral constriction of constituent cells and unidirectional binary fission of the ellipsoidal MMPs. This finding suggests the evolution toward MMPs multicellularity via the mechanism of incomplete separation of offspring. Remarkably, thousands of flagellar at the periphery surface of cells underpin the coordinated swimming of MMPs in response to mechanical, chemical, magnetic and optical stimuli, including a magnetotactic photokinesis behaviour. Together these results unveil the unique structure and function property of ellipsoidal MMPs.
Published: 2020

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