Laurence Lemelle

Laurence Lemelle
Ecole normale supérieure de Lyon | ENS Lyon · UMR 5276 - Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL - TPE)

Doctor of Philosophy

About

116
Publications
9,557
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3,311
Citations
Introduction
• Trace metals in single microfossils and microbial cells. The metallome, metal&sulfur specifications and molecular forms, and metal/sulfur spatial distribution as biomarkers and biological process fingerprints. • Search for microbial life traces on solid surfaces and in meteorites applied to Sample Return Missions from space. • Primo interactions of microorganisms with solid surfaces, with medical, environmental, and spatial applications. • Nano-XRF/XANES with synchrotron hard X-rays
Additional affiliations
October 1999 - present
French National Centre for Scientific Research
Position
  • Research scientist (CR1)
October 1999 - present
Ecole normale supérieure de Lyon
Position
  • Researcher

Publications

Publications (116)
Article
Full-text available
Future long-duration human spaceflight will require developments to limit biocontamination of surface habitats. The MATISS (Microbial Aerosol Tethering on Innovative Surfaces in the international Space Station) experiments allowed for exposing surface treatments in the ISS (International Space Station) using a sample-holder developed to this end. T...
Article
Full-text available
Subsurface habitats on Earth host an extensive extant biosphere and likely provided one of Earth’s earliest microbial habitats. Although the site of life’s emergence continues to be debated, evidence of early life provides insights into its early evolution and metabolic affinity. Here, we present the discovery of exceptionally well-preserved, ~3.42...
Article
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Future long-duration human spaceflight calls for developments to limit biocontamination of the surface habitats. The MATISS experiment tests surface treatments in the ISS’s atmosphere. Four sample holders were mounted with glass lamella with hydrophobic coatings, and exposed in the Columbus module for ~6 months. About 7800 particles were detected b...
Article
Full-text available
Sub-cellular trace element quantifications of nano-heterogeneities in brain tissues offer unprecedented ways to explore at elemental level the interplay between cellular compartments in neurodegenerative pathologies. We designed a quasi-correlative method for analytical nanoimaging of the substantia nigra, based on transmission electron microscopy...
Article
Full-text available
Bioactive metal releases in ocean surface water, such as those by ash falls during volcanic super-eruptions, might have a potentially toxic impact on biocalcifier planktic microorganisms. Nano-XRF imaging with the cutting-edge synchrotron hard X-ray nano-analysis ID16B beamline (ESRF) revealed for the first time a specific Zn- and Mn-rich banding p...
Article
Bacteria tumble periodically, following environmental cues. Whether they can tumble near a solid surface is a basic issue for the inception of infection or mineral biofouling. Observing freely swimming Escherichia coli near and parallel to a glass surface imaged at high magnification (×100) and high temporal resolution (500 Hz), we identified tumbl...
Article
X‐ray analysis was introduced at the beginning of the twentieth century, right after the discovery of X‐rays. It represents a specific group of methods of investigation of samples that share the same probe, the X‐rays, and produces nondestructive, highly varied results of the intrinsic properties of specimens. X‐ray fluorescence (XRF) is the main m...
Article
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X-ray spectroscopic techniques have proven to be particularly useful in elucidating the molecular and electronic structural information of chemically heterogeneous and complex micro- and nano-structured materials. However, spatially resolved chemical characterization at the micrometre scale remains a challenge. Here, we report the novel hyperspectr...
Article
Mineral inventories of enstatite chondrites; (EH and EL) are strictly dictated by combined parameters mainly very low dual oxygen (fO2) and sulfur (fS2) fugacities. They are best preserved in the Almahata Sitta MS-17, MS-177 fragments, and the ALHA 77295 and MAC 88136 Antarctic meteorites. These conditions induce a stark change of the geochemical b...
Article
Quantitative nano-imaging of metal traces in a solid is a recent capability arising from the construction of hard X-ray nanoprobes dedicated to X-ray Fluorescence (XRF) imaging on upgraded third generation synchrotrons. Micrometer sample preparation valid for trace analysis is a fundamental part of the required developments to capitalize on the red...
Article
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For most pathogenic bacteria, flagellar motility is recognized as a virulence factor. Here, we analysed the swimming behaviour of bacteria close to eukaryotic cellular surfaces, using the major opportunistic pathogen Pseudomonas aeruginosa as a model. We delineated three classes of swimming trajectories on both cellular surfaces and glass that coul...
Article
The NASA Stardust mission used silica aerogel slabs to slowly decelerate and capture impinging cosmic dust particles for return to Earth. During this process, impact tracks are generated along the trajectory of the particle into the aerogel. It is believed that the morphology and dimensions of these tracks, together with the state of captured grain...
Article
Hard X-ray, quantitative, fluorescence elemental imaging was performed on the ID22NI nanoprobe and ID22 microprobe beam lines of the European Synchrotron Research facility (ESRF) in Grenoble, France, on eight interstellar candidate impact features in the framework of the NASA Stardust Interstellar Preliminary Examination (ISPE). Three features were...
Article
With the discovery of bona fide extraterrestrial materials in the Stardust Interstellar Dust Collector, NASA now has a fundamentally new returned sample collection, after the Apollo, Antarctic meteorite, Cosmic Dust, Genesis, Stardust Cometary, Hayabusa, and Exposed Space Hardware samples. Here, and in companion papers in this volume, we present th...
Article
Here, we report the identification of 69 tracks in approximately 250 cm2 of aerogel collectors of the Stardust Interstellar Dust Collector. We identified these tracks through Stardust@home, a distributed internet-based virtual microscope and search engine, in which > 30,000 amateur scientists collectively performed >9 9 107 searches on approximatel...
Article
We report the quantitative characterization by synchrotron soft X-ray spectroscopy of 31 potential impact features in the aerogel capture medium of the Stardust Interstellar Dust Collector. Samples were analyzed in aerogel by acquiring high spatial resolution maps and high energy-resolution spectra of major rock-forming elements Mg, Al, Si, Fe, and...
Article
We discuss the inherent difficulties that arise during "ground truth" characterization of the Stardust interstellar dust collector. The challenge of identifying contemporary interstellar dust impact tracks in aerogel is described within the context of background spacecraft secondaries and possible interplanetary dust particles and beta-meteoroids....
Article
Under the auspices of the Stardust Interstellar Preliminary Examination, picokeystones extracted from the Stardust Interstellar Dust Collector were examined with synchrotron Fourier transform infrared (FTIR) microscopy to establish whether they contained extraterrestrial organic material. The picokeystones were found to be contaminated with varying...
Article
Here, we report analyses by synchrotron X-ray fluorescence microscopy of the elemental composition of eight candidate impact features extracted from the Stardust Interstellar Dust Collector (SIDC). Six of the features were unambiguous tracks, and two were crater-like features. Five of the tracks are so-called "midnight" tracks-that is, they had tra...
Article
The NASA Stardust spacecraft exposed an aerogel collector to the interstellar dust passing through the solar system. We performed X-ray fluorescence element mapping and abundance measurements, for elements 19 <= Z <= 30, on six "interstellar candidates," potential interstellar impacts identified by Stardust@Home and extracted for analyses in picoke...
Article
On the basis of an interstellar dust model compatible with Ulysses and Galileo observations, we calculate and predict the trajectories of interstellar dust (ISD) in the solar system and the distribution of the impact speeds, directions, and flux of ISD particles on the Stardust Interstellar Dust Collector during the two collection periods of the mi...
Article
The Stardust Interstellar Preliminary Examination team analyzed thirteen Al foils from the NASA Stardust interstellar collector tray in order to locate candidate interstellar dust (ISD) grain impacts. Scanning electron microscope (SEM) images reveal that the foils possess abundant impact crater and crater-like features. Elemental analyses of the cr...
Article
Full-text available
Seven particles captured by the Stardust Interstellar Dust Collector and returned to Earth for laboratory analysis have features consistent with an origin in the contemporary interstellar dust stream. More than 50 spacecraft debris particles were also identified. The interstellar dust candidates are readily distinguished from debris impacts on the...
Article
Full-text available
We report experimental evidence that Mg isotopes may be used as a geochemical tracer of biological activity. In contrast to H, O, C, N, and S, Mg is immune to atmospheric effects and therefore paves the way for the identification of ancient and/or extraterrestrial biological traces. The present work shows experimentally that, in the presence of oli...
Article
Using synchrotron-based X-ray diffraction measurements, we identified crystalline material in two particles of extraterrestrial origin extracted from the Stardust Interstellar Dust Collector. The first particle, I1047,1,34 (Hylabrook), consisted of a mosaiced olivine grain approximately 1 mu m in size with internal strain fields up to 0.3%. The uni...
Article
Full-text available
The orientation of the circular motion of most swimming E. coli at a solid surface is shown to be (i) reversed by supplementing the medium with alginate and (ii) restored by rendering the glass surface positively charged. Given slip promotion by the polymer and suppression by its anchoring on the surface, observations are interpreted by slip at the...
Article
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Chemical weathering of Mg, Ca-silicates and alumino-silicates contributes significantly to the drawdown of atmospheric CO2 over long time scales. The present work focuses on how this mode of weathering may change in the presence of free-living bacteria in oligotrophic waters, which compose most of the surface freshwaters of the Earth. Forsterite (F...
Article
Polyadenylation is recognized as part of a surveillance machinery for eliminating defective RNA molecules in eukaryotes and prokaryotes. Escherichia coli strains, deficient in poly(A)polymerase I (PAP I), expressed less flagellin compared to wild-type strains. Because flagellin synthesis is a late step in the flagellar biosynthesis pathway, we asse...
Article
Timing the appearance of photosynthetic microorganisms is crucial to understanding the evolution of life on Earth. The ability of the biosphere to use sunlight as a source of energy (photoautotrophy)would have been essential for increasing biomass and for increasing the biogeochemical capacity of all prokaryotes across the range of redox reactions...
Article
Full-text available
Introduction: In 2000 and 2002 the Stardust Mission exposed aerogel collector panels for a total of about 200 days to the stream of interstellar grains sweeping through the solar system [1]. The material was brought back to Earth in 2006. The goal of this work is the laboratory calibration of the collection process by shooting high speed [5 -30km/s...
Article
Full-text available
Special Issue: 74th Annual Meeting of the Meteoritical Society, August 8-12, 2011, London, U.K.
Article
Sulfur speciation in a comprehensive set of insoluble organic matter (IOM) samples extracted from 3 CI (Orgueil, Alais, Ivuna), 5 CM (QUE97990, Murchison, Murray, QUE99355, Cold Bokkeveld), 1 CR (Renazzo) and ungrouped C2 Tagish Lake chondrites has been studied by K-edge XANES micro-spectroscopy. Five main sulfur groups were identified: (1) sulfide...
Article
Full-text available
Flagellar propulsion of swimming Escherichia coli produces circling clockwise motions near planar solid surfaces. Counterclockwise motion was first reported near air-TN medium interfaces, showing that slip at the interface is a key parameter of bacterial swimming.
Conference Paper
Full-text available
73rd Annual Meeting of the Meteoritical-Society, New York, NY, July 26-30, 2010
Article
Full-text available
73rd Annual Meeting of the Meteoritical-Society : New York, NY, July 26-30, 2010
Article
Data acquisition and reconstruction for tomography have been extensively studied for the past 30 years, mainly for medical diagnosis and non-destructive testing. In these fields, imaging is typically limited to sample morphology. However, in many cases, that is insufficient, and 3D chemical imaging becomes essential.This review highlights synchrotr...
Article
Exceptional preservation of aragonite in a circa 3.3 billion year old microbial mat from the Barberton greenstone belt, South Africa Frances Westall, Barbara Cavalazzi, Laurence Lemelle, Yves Marrocchi, Jean-Noël Rouzaud, Alexandre Simionovici, Murielle Salomé, Smail Mostefaoui, Caroline Andreazza, Frédéric Foucher, Jan Toporski, Andrea Jauss, Volk...
Article
Here we describe the critical role that synchrotron X‐ray and infrared microprobes are playing in the search for interstellar dust in the Stardust Interstellar Dust Collector (SIDC). The samples under examination are submicron particles trapped in low‐density aerogel. We have found that the spatial resolution, energy range, and flux capabilities of...
Article
Abstract— An analytical transmission electron microscopy (ATEM) study was undertaken in order to better understand the formation conditions of dusty olivines (i.e., olivines containing abundant tiny inclusions of Fe-Ni metal) in primitive meteorites. Dusty olivines from type I chondrules in the Bishunpur chondrite (LL3.1) and from synthetic samples...
Article
Introduction: In preparation for the upcoming International Mars Sample Return mission (MSR), returning samples containing potential biohazards, we have implemented a hyperspec-tral method of in-situ analysis of grains performed in BSL4 quarantine conditions, by combining several non-destructive imaging diagnostics. This allows sample transportatio...
Article
Microbial structures on the Early Archaean Earth are µm- scale in size although communities and mats may form larger assemblages up to the cm-scale. The small size of the structures necessitates the use of specialised complementary analytical techniques to characterise them and to ascertain their biogenicity. We used synchrotron radiation and NanoS...
Article
CI, CM, CR and ungrouped C2 carbonaceous chondrites contain a few percents of insoluble organic matter (IOM), which could have a presolar origin and provide clues on carbon chemistry in interstellar medium of protostellar environments. However, these chondrites have experienced complex hydrothermal processes in their parent bodies [1-3]. A major is...
Article
Sulfur oxidation state of insoluble OM from 3 CI1, 5 CM2, Renazzo (CR2) and Tagish Lake was determined by S-XANES. Different redox ratios are reported among these chondrites, possibly evidencing chemical effects of hydrothermalism.
Article
A method and a sample holder for analysis in quarantine conditions of Mars return samples is presented.
Article
Two selected case studies (Stardust keystones and Draken's Neoproterozoic cells) exemplify the relevance of micro-X-ray fluorescence at the S K-edge performed at the ID21 beamline of the ESRF to search for traces of life in extraterrestrial samples.
Article
Full-text available
The Stardust Interstellar Preliminary Examination (ISPE) is a three-year effort to characterize the Stardust interstellar dust collection and collector using non-destructive techniques. We summarize the status of the ISPE.
Article
Magnesium is a major element in both microbial cells and minerals, immune to redox conditions and atmospheric interactions. In organic cells, Mg can be associated with membranes, with cytoplasm (either as an isolated ion or bound to proteins). Its isotope composition can be used to constrain the contribution of organic material to carbonate fluxes...
Article
A hard x-ray nanoprobe has been implemented at the synchrotron in Grenoble, France, allowing nondestructive trace element imaging of thick samples. Its advantages are nanometer spatial resolution on samples of several tens of micrometer, very high flux, and achromaticity. Nanometer imaging of a cometary grain from the NASA Stardust mission shows th...
Article
The Josefdal Chert (3.33 Ga), Barberton, contains a superbly preserved microbial mat. High resolution geochemical profiling across the mat documents textures and compositions indicative of a mixed microbial community of anoxygenic photosynthesisers and probably SRBs.