Pauline Vannier

Matis ltd. | Matis · Food safety, Environment and Genetics

Surface microbes are aerosolized into the atmosphere by wind and events such as dust storms, wildland fires, and volcano eruptions. Only microbial cells that survive the various atmospheric stressors during their transportation will deposit and colonize new environments. These stressors include desiccation, oxidative stress, solar radiation, osmoti...

Phytoplankton play a crucial role in the marine food web and are sensitive indicators of environmental change. Iceland is at the center of a contrasting hydrography, with cold Arctic water coming in from the north and warmer Atlantic water from the south, making this geographical location very sensitive to climate change. We used DNA metabarcoding...

Skaftárkatlar are two subglacial lakes located beneath the Vatnajökull ice cap in Iceland associated with geothermal and volcanic activity. Previous studies of these lakes with ribosomal gene (16S rDNA) tag sequencing revealed a limited diversity of bacteria adapted to cold, dark, and nutrient-poor waters. In this study, we present analyses of meta...

Surface microbes are aerosolized into the atmosphere by wind and events such as dust storms and volcanic eruptions. Before they reach their deposition site, they experience stressful atmospheric conditions which preclude the successful dispersal of a large fraction of cells. In this study, our objectives were to assess and compare the atmospheric a...

The North Atlantic Ocean surrounds Iceland, influencing its climate and hosting a rich ecosystem that provides the Icelandic nation with economically valuable marine species. The basis of the Icelandic marine ecosystem consists of communities of diverse microorganisms including bacteria, archaea, and unicellular eukaryotes. While the primary produc...

The oceanic crust is the world’s largest and least explored biosphere on Earth. The basaltic subsurface of Surtsey island in Iceland represents an analog of the warm and newly formed-oceanic crust and offers a great opportunity for discovering novel microorganisms. In this study, we collected borehole fluids, drill cores, and fumarole samples to ev...

Novel thermophilic heterotrophic bacteria were isolated from the subsurface of the volcanic island Surtsey off the south coast of Iceland. The strains were isolated from tephra core and borehole fluid samples collected below 70 m depth. The Gram-negative bacteria were rod-shaped (0.3–0.4 µm wide, 1.5–7 µm long), aerobic, non-sporulating and non-mot...

During RV MS Merian expedition MSM75, an international, multidisciplinary team explored the Reykjanes Ridge from June to August 2018. The first area of study, Steinahóll (150–350 m depth), was chosen based on previous seismic data indicating hydrothermal activity. The sampling strategy included ship- and AUV-mounted multibeam surveys, Remotely Oper...

The island of Surtsey was formed in 1963–1967 on the offshore Icelandic volcanic rift zone. It offers a unique opportunity to study the subsurface biosphere in newly formed oceanic crust and an associated hydrothermal-seawater system, whose maximum temperature is currently above 120°C at about 100m below surface. Here, we present new insights into...

Marine microorganisms contribute to the health of the global ocean by supporting the marine food web and regulating biogeochemical cycles. Assessing marine microbial diversity is a crucial step towards understanding the global ocean. The waters surrounding Iceland are a complex environment where relatively warm salty waters from the Atlantic cool d...

Background Extreme terrestrial, analogue environments are widely used models to study the limits of life and to infer habitability of extraterrestrial settings. In contrast to Earth’s ecosystems, potential extraterrestrial biotopes are usually characterized by a lack of oxygen. Methods In the MASE project (Mars Analogues for Space Exploration), we...

Five bacterial (facultatively) anaerobic strains, namely Buttiauxella sp. MASE-IM-9, Clostridium sp. MASE-IM-4, Halanaerobium sp. MASE-BB-1, Trichococcus sp. MASE-IM-5, and Yersinia intermedia MASE-LG-1 isolated from different extreme natural environments were subjected to Mars relevant environmental stress factors in the laboratory under controlle...

Five bacterial (facultatively) anaerobic strains, namely Buttiauxella sp. MASE-IM-9, Clostridium sp. MASE-IM-4, Halanaerobium sp. MASE-BB-1, Trichococcus sp. MASE-IM-5, and Yersinia intermedia MASE-LG-1 isolated from different extreme natural environments were subjected to Mars relevant environmental stress factors in the laboratory under controlle...

One of the main objectives for astrobiology is to unravel and explore the habitability of environments beyond Earth, paying special attention to Mars. If the combined environmental stress factors on Mars are compatible with life or if they were less harsh in the past, to investigate the traces of past or present life is critical to understand its p...

The 2017 Surtsey Underwater volcanic System for Thermophiles, Alteration processes and INnovative concretes (SUSTAIN) drilling project at Surtsey volcano, sponsored in part by the International Continental Scientific Drilling Program (ICDP), provides precise observations of the hydrothermal, geochemical, geomagnetic, and microbiological changes tha...

Growth in sodium chloride (NaCl) is known to induce stress in non-halophilic microorganisms leading to effects on the microbial metabolism and cell structure. Microorganisms have evolved a number of adaptations, both structural and metabolic, to counteract osmotic stress. These strategies are well-understood for organisms in NaCl-rich brines such a...

Principal Component Analysis (PCA) plot showing the multivariate variation among the three sample sets (control, NaCl stressed and MgSO4 stressed; n = 3) in terms of the obtained peaks.

List of identified and putatively identified lipids. Metabolite levels for each experimental group are shown. Levels are expressed as mean peak intensity relative to the mean peak intensity of the control group. Numbers indicated in bold indicates statistically significance (p < 0.05).

Four facultative anaerobic and two obligate anaerobic bacteria were isolated from extreme environments (deep subsurface halite mine, sulfidic anoxic spring, mineral-rich river) in the frame MASE (Mars Analogues for Space Exploration) project. The isolates were investigated under anoxic conditions for their survivability after desiccation up to six...

The artificial mineralization of a polyresistant bacterial strain isolated from an acidic, oligotrophic lake was carried out to better understand microbial (i) early mineralization and (ii) potential for further fossilisation. Mineralization was conducted in mineral matrixes commonly found on Mars and Early-Earth, silica and gypsum, for 6 months. S...

The limits of life of aerobic microorganisms are well understood, but the responses of anaero-bic microorganisms to individual and combined extreme stressors are less well known. Motivated by an interest in understanding the survivability of anaerobic microorganisms under Martian conditions, we investigated the responses of a new isolate, Yersinia...

Results of the API R 20 A and Rapid ID 32 A tests. + Y. intermedia MASE-LG-1 metabolized the named substance; − Y. intermedia MASE-LG-1 did not metabolize the named substance. (DOCX)

Dendrogram Y. intermedia MASE-LG-1. Neighbor-joining tree based on 16S rDNA sequences showing the phylogenetic position of Y. intermedia MASE-LG-1 related to 14 species of the genus Yersinia. DNA sequences were aligned using BioEdit. The dendrogram was constructed by using MEGA6. Bar: 0.01 substitutions per nucleotide position. (TIF)

Astrobiology seeks to understand the limits of life and to determine the physiology of organisms in order to better assess the habitability of other worlds. To successfully achieve these goals we require microorganisms from environments on Earth that approximate to extraterrestrial environments in terms of physical and/or chemical conditions. The m...

The concept of present and/or past extraterrestrial life is thrilling and tackled intensively throughout the last decades, yet remains notional. Some regions of extraterrestrial bodies (e.g. the Mars) are in general considered as habitable; however, are ruled by extreme physical and chemical variables, which constrain the possibility of life. Simil...

Osmotic stress is one of the major limitations for cell growth. Microorganisms can evolve adaptations to abiotic stresses like high salt concentrations in the environment. Sensor and signal transduction networks provide information to the cell about the osmolarity of its surroundings leading to an immediate metabolic response to counteract the osmo...

The search for traces of life is one of the principal aims of Mars exploration. Within the MASE project (Mars Analogues for Space Exploration) we work to improve approaches and methods for biomarker detection and extraction from Mars analogue sites. One promising strategy to study the preservation of biosignatures in Mars conditions consists of the...

During the development of the Mars Analogues for Space Exploration project (MASE) several microbial isolates of the Tessaracoccus genus, a denitrifying actynomicetes, were obtained from enrichment cultures of samples from cores drilled at different depths in the Iberian Pyrite Belt. Some of these strains, isolates SSRT5 and SSRT8, were subjected to...

Marine microbial biogeography describes the occurrence and abundance of microbial taxa and aims to understand the mechanisms by which they are dispersed and then adapt to their environment. The development of novel technologies, such as Next-Generation Sequencing (NGS) in combination with large-scale ocean sampling campaigns, generated a vast amoun...

In this chapter the current knowledge of the diversity of piezophiles isolated so far is reviewed. The isolated piezophiles originated from high-pressure environments such as the cold deep sea, hydrothermal vents, and crustal rocks. Several “stress” conditions can be experienced in these environments, in particular high hydrostatic pressure (HHP)....

A novel hyperthermophilic, piezophilic anaerobic archaeon, designated as NCB100T, was isolated from a hydrothermal vent flange fragment collected in the Guaymas basin at the hydrothermal vent site named "Rebecca's Roost" at a depth of 1997 m. Enrichment and isolation were done at 100°C under atmospheric pressure. Cells of strain NCB100T are highly...

We report here the complete sequence and fully manually curated annotation of the genome of strain Ch5, a new member of the piezophilic hyperthermophilic species Thermococcus barophilus .

Life is a physico-chemical process by which tell-tale signals or traces are left on the environment. These signals are indicators of life and are known as biomarkers. Besides, the traces of some kinds of microorganisms can be well preserved, provided that they are rapidly mineralized and that the sediments in which they occur are rapidly cemented [...

Introduction: The Life Detection System (LDS) is designed as a two modules system for microbial life detection under growing conditions. The microbes growth is followed by redox, pH and conductivity parameters but others parameters can be monitored as well if needed. The experiments presented in this paper follow the physicochemical parameter in a...

MASE (Mars Analogues for Space Exploration) is a four year collaborative research project supported by an EC FP7 contract. Its aim is to understand how combined environmental stresses affect the habitability of a number of Mars analogue environments on Earth, specifically for anaerobic organisms. Crucial to assessing the habitability of any environ...

The search for life beyond Earth is challenging and requires, as a prerequisite, intensive research on microbial life in similar, extreme environments on Earth. Mars analogue sites are characterised by e.g. anoxic conditions, organic compound limitation, low temperatures, high salinity or presence of oxidising compounds, and consequently represent...

Assessing the habitability of Mars and detecting life, if it was ever there, depends on knowledge of whether the combined environmental stresses experienced on Mars are compatible with life and whether a record of that life could ever be detected. Many combinations of Mars relevant stress factors, such as high radiation dose rates and high UV uence...

The MASE (Mars Analogues for space exploration) project intends to gain deeper insights into the habitability of Mars by searching for anaerobic extremophiles in Mars analogue environments on Earth like the cold sulfidic springs in Germany, the deep-subsurface salt mine in UK, the iron-rich Rio Tinto and the cold acidic lake Graenavatn in lceland....

The MASE (Mars Analogues for Space Exploration) [1] project is a four-year collaborative research project supported by the European Commission Seventh Framework Contract. The aim of the project is to understand how combined environmental stresses influence the habitability of a number of Mars analogue environments in Europe and beyond. Field sites...

Is life out there? In order to assess the habitability of Mars, which is (or has been) the most Earth-like planet in our Solar System, the first step is to investigate microorganisms thriving in terrestrial biotops with Mars similar conditions (0.13% O₂ in the atmosphere, low nutrients, low temperatures, high salinity and oxidising compounds, acidi...

Astrobiology seeks to understand the limits of life and to determine the physiology of organisms in order to be able to better assess the potential habitability of other worlds and improve our ability to assay them for the presence of life. To successfully achieve this we require representative microorganisms from environments on Earth that in phys...

Transcriptomes were analyzed for two related hyperthermophilic archaeal species, the piezophilic Thermococcus barophilus strain MP and piezosensitive Thermococcus kodakarensis strain KOD1 subjected to high hydrostatic pressures. A total of 378 genes were differentially expressed in T. barophilus cells grown at 0.1, 40 and 70 MPa, whereas 141 genes...

Colonization of life on Surtsey has been observed systematically since the formation of the island 50 years ago. Although the first colonisers were prokaryotes, such as bacteria and blue–green algae, most studies have been focused on the settlement of plants and animals but less on microbial succession. To explore microbial colonization in diverse...

Colonisation of life on Surtsey has been observed systematically since the formation of the island 50 years ago. Although the first colonisers were prokaryotes, such as bacteria and blue-green algae, most studies have been focusing on settlement of plants and animals but less on microbial succession. To explore microbial colonization in diverse soi...

MASE is a collaborative, four-year research project supported by the European Commission's Seventh Framework Programme (FP7). This project started in January 2014 and its main objectives are to perform experimental studies to investigate how selected anaerobic microorganisms collected from Mars analogue sites on Earth respond to stress and fossiliz...

Marinitoga piezophila KA3 is a thermophilic, anaerobic, chemoorganotrophic, sulfur-reducing bacterium isolated from the Grandbonum deep-sea hydrothermal vent site at the East Pacific Rise (13°N, 2,630-m depth). The genome of M. piezophila KA3 comprises a 2,231,407-bp circular chromosome and a 13,386-bp circular plasmid. This genome was sequenced wi...

Thermococcus barophilus is a hyperthermophilic, anaerobic, mixed heterotrophic, and carboxydotrophic euryarchaeon isolated from the deep sea hydrothermal vent Snakepit site on the mid-Atlantic ridge at a depth of 3,550 m. T. barophilus is the first true piezophilic, hyperthermophilic archaeon isolated, having an optimal growth at 40 MPa. Here we re...