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Monternier Pierre-Axel, Marmillot Vincent, Rouanet Jean-Louis, Roussel Damien, . (2014). Mitochondrial phenotypic flexibility enhances energy savings during winter fast in king penguin chicks
. J. Exp. Biol., 217 (15 ), 2691–2697 .
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. (2013). Experimental fossilization of the Thermophilic Gram-positive Bacterium Geobacillus SP7A: A Long Duration Preservation Study
. Geomicrobiol. J., 31(7), 578–589.
Abstract: Recent experiments to fossilize microorganisms using silica have shown that the fossilization process is far more complex than originally thought; microorganisms not only play an active role in silica precipitation but may also remain alive while silica is precipitating on their cell wall. To better understand the mechanisms that lead to the preservation of fossilized microbes in recent and ancient rocks, we experimentally silicified a Gram-positive bacterium, Geobacillus SP7A, over a period of five years. The microbial response to experimental fossilization was monitored with the use of LIVE/DEAD staining to assess the structural integrity of the cells during fossilization. It documented the crucial role of silicification on the preservation of the cells and of their structural integrity after several years. Electron microscopy observations showed that initial fossilization of Gram-positive bacteria was extremely rapid, thus allowing very good preservation of Geobacillus SP7A cells. A thick layer of silica was deposited on the outer surface of cell walls in the earliest phase of silicification before invading the cytoplasmic space. Eventually, the cell wall was the only recognizable feature. Heavily mineralized cells thus showed morphological similarities with natural microfossils found in the rock record.
Programme: 1077
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. (2014).
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. (2014). TALISKER 1077 IPEV, Chemical transfers across the lithosphere of Kerguelen: from the mantle to the ocean..
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. (2014).
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Van de Vijver Bart, de Haan Myriam, Lange-Bertalot Horst, . (2014). Revision of the genus Eunotia (Bacillariophyta) in the Antarctic Region
. Plant Ecology and Evolution, 147(2), 256–284.
Keywords: ANTARCTIC REGION, BACILLARIOPHYTA, BIOGEOGRAPHY, EUNOTIA, MORPHOLOGY, NEW SPECIES, TAXONOMY,
Programme: 136
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Hamilton Paul B, de Haan Myriam, Zidarova Ralitsa, Van de Vijver Bart, . (2013). An evaluation of selected Neidium species from the Antarctic region
. Diatom Res., 29(1), 27–40.
Abstract: The presentation of three distinct Neidium taxa from the sub-Antarctic and Maritime Antarctic region after examining more than 1500 samples from a broad variety of aquatic and terrestrial (micro-)habitats suggests that taxa representing the genus Neidium Pfitzer are not only quite rare in these regions, but that the three species also represent well-defined biogeographical distributions. N. nyvltii sp. nov., N. antarcticum sp. nov. and N. aubertii Manguin are characterized by linear to linear?lanceolate valves with rostrate to capitate apices, a single prominent longitudinal canal along the valve margins and lacinia covering the distal raphe endings. Neidium nyvltii is a benthic alkalophile growing in the Maritime Antarctic region under high total phosphorus (TP) and moderately high chloride concentrations, while the closest taxa for comparison (N. kozlowii Mereschkowsky and its varieties) are also alkalophilic, growing under lower TP concentrations in northern temperate?Arctic regions. Neidium aubertii is an acidophile with a sub-Antarctic distribution, whereas the most comparable taxa are N. bisulcatum (Lagestedt) Cleve, and N. bergii (A. Cleve-Euler) Krammer & Lange-Bertalot both are alkalophiles with northern hemisphere distribution and commonly occurring in the Arctic. There is some evidence of parallel similarities in valve forms between the polar northern and southern hemispheres. The significance of this parallelism is yet to be determined.
Programme: 136
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E. Le Meur, M. Sacchettini, S. Garambois, E. Berthier, A. S. Drouet, G. Durand, D. Young, J. S. Greenbaum, D. D. Blankenship, J. W. Holt, E. Rignot, J. Mouginot, Y. Gim, D. Kirchner, B. de Fleurian, O. Gagliardini and F. Gillet-Chaulet. (2014).
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. (2014).
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. (2014). Geophysical Journal International , 198 (1 ), 285–297 .
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