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MARNAUT 2007. Organic biogeochemical studies within MARNAUT 2007. Nicolas Chevalier, Ioanna Bouloubassi (LOCEAN). Objectives Approaches Sampling Collaborative work. MARNAUT 2007. Organic biogeochemical studies within MARNAUT 2007. Nicolas Chevalier, Ioanna Bouloubassi (LOCEAN).
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MARNAUT 2007 Organic biogeochemical studies within MARNAUT 2007 Nicolas Chevalier, Ioanna Bouloubassi (LOCEAN) Objectives Approaches Sampling Collaborative work
MARNAUT 2007 Organic biogeochemical studies within MARNAUT 2007 Nicolas Chevalier, Ioanna Bouloubassi (LOCEAN) Objectives Approaches Samples Collaborative work
To assess microbial assemblages and microbially-driven biogeochemical processes related to active and past fluid seepage at cold seeps in the Marmara Sea To link biogeochemical processes and microbial assemblages to fluid seepage patterns and dynamics > > > > MARNAUT 2007 Organic biogeochemical studies within MARNAUT 2007 Objectives
MARNAUT 2007 Organic biogeochemical studies within MARNAUT 2007 Objectives More specifically we aim at : Defining the structure, diversity and functionning of microbial assemblages involved in the transformation of fluid components (e.g., methane oxidation, sulphate reduction, sulphide oxidation...) Understanding how microbial assemblages (and associated processes) respond to varying seepage activity, compostion and chemistry of fluids, flow rates... and how they impact on the precipitation of authigenic mineralsand on cold-seep macrofauna > > > >
X’ O Molecular Tools : lipid biomarkers microbial cell membrane lipids as sources information (biomarkers) on the composition and biogeochemistry of microbial assemblages • Distinctive ‘taxonomic’ structural features > > community structure • Concentrations > > relative abundances of microbial groups • > > biomass of extant (active) organisms • Stable carbon isotopes > > carbon source utilized, carbon flow > > X O OH MARNAUT 2007 OH O X O Organic biogeochemical studies within MARNAUT 2007 Approaches
MARNAUT 2007 Organic biogeochemical studies within MARNAUT 2007 Approaches Molecular Tools : lipid biomarkers
MARNAUT 2007 Organic biogeochemical studies within MARNAUT 2007 Approaches Lipid biomarkers : analytical methods • Solvent extraction of lipids • Chromatographic isolation of lipid biomarker classes • Gas chromatography (GC) • Gas chromatography-mass spectrometry (GC-MS) • Isotope ratio monitoring-gas chromatography-mass spectrometry (GC-irMS) * • High performance liquid chromatography- mass spectrometry (HPLC-MS) * • * in collaboration
MARNAUT 2007 Organic biogeochemical studies within MARNAUT 2007 Samples Undisturbed Sediments Cores Authigenic Crusts Microbial Mats, Benthic Fauna Samples to be taken in contrasted settings : Varying fluid seepage Different benthic activity To be sub-sampled and conditionned on board And to be shared for coupled investigations
MARNAUT 2007 Organic biogeochemical studies within MARNAUT 2007 Collaborative Work This contribution to the MARNAUT project is viewed as part of an integrated biogeochemical approach and, as such, it requires strong interdisciplinary coupling More specifically we plan to tightly couple this study with: Microbiology and molecular biology approaches (P. Lopez) Fluid analyses and fluxes, biogeochemical reaction rates, transport/reaction models (V. Aloisi) Authigenic carbonate geochemistry (C. Pierre) Biology of benthic fauna (Ifremer, Brest)
MARNAUT 2007 Previous and ongoing work at cold seeps in the framework of MEDIFLUX (ESF) BIOZAIRE (IFREMER/TOTAL) HERMES (EU)
C25 isoprenoids PMI:0 PMI:1-3 C20 isoprenoids Cr Squ:0 Cr:1 H H C25 isoprenoids PMI:3-5 MARNAUT 2007 C30 isoprenoids Squ: 3-6 C35 isoprenoids . Biomarkers in Crusts (Olimpi mud volcano area - MEDINAUT) Apolar compounds Bouloubassi et al., (2006)
OH X O O O O X OH OH X’ O X O I Archaeol MARNAUT 2007 II IId IIa Hydroxyarchaeol IIc IIb Ib Ic Biomarkers in Crusts (Olimpi mud volcano area-MEDINAUT) Polar compounds Bouloubassi et al., (2006); Aloisi et al., 2002; Pancost et al., 2001
ia15 FAME BisHomo-acid Archaeol OH-Archaeol n-29 Alkane PMI:1-5 cholesterol BisHomo-ol Diethers II Diethers I ia17 FAME DGDT PMI - 2 0 E - 4 0 B d13C ‰ - 6 0 B B - 8 0 A MARNAUT 2007 - 1 0 0 Biomarkers in Crusts (Olimpi & Anaximander mud volcano area) Bouloubassi et al., (2006)
OH X O O NL 20 CC1 O O X OH OH X’ O X O Dialkyl Glycerol Diethers (DGD) MARNAUT 2007 NAUTINIL 2003 Polar lipid patterns in carbonate crusts Caldera Archaeol Hydroxyarchaeol Pockmarks NL 14 CC5 ...and suite of sterols, alcohols, hopanols
PMI hopanoïdes crocetane MARNAUT 2007 n-alcanes (C14 – C34) : essentiellement sources terrigènes C20 et C25 Isoprénoïdes irréguliers : sources microbiennes - Archées Hopanoïdes (hopanes-hopènes, C27 - C32 : sources microbiennes - Bactéries BIOZAIRE GC/MS : Fraction hydrocarbures