Objectif
Methane, a key greenhouse gas, is cycled by microorganisms via two pathways, aerobically and anaerobically. Research on the
marine methane cycle has mainly concentrated on anaerobic processes. Recent biomarker work has provided compelling
evidence that aerobic methane oxidation (AMO) can play a more significant role in cycling methane emitted from sediments than
previously considered. AMO, however, is not well studied requiring novel proxies that can be applied to the sedimentary record. A
group of complex lipids biosynthesised by aerobic methanotrophs known as aminobacteriohopanepolyols represent an ideal target
for developing such poxies. Recently BHPs have been identified in a wide range of modern and recent environments including a
continuous record from the Congo deep sea fan spanning the last 1.2 million years.
In this integrated study, the regulation and expression of BHP will be investigated and calibrated against environmental variables
including temperature, pH, salinity and, most importantly, methane concentrations. The work program has three complementary
strands. (1) Pure culture and sedimentary microcosm experiments providing an approximation to natural conditions. (2) Calibration
of BHP signatures in natural marine settings (e.g. cold seeps, mud volcanoes, pockmarks) against measured methane gradients.
(3) Application of this novel approach to the marine sedimentary record to approximate methane fluxes in the past, explore the age
and bathymetric limits of this novel molecular proxy, and identify and potentially 14C date palaeo-pockmarks structures. Crucial to
the success is also the refinement of the analytical protocols to improve both accuracy and sensitivity, using a more sensitive
analytical instrument (triple-quadrupole mass spectrometer).
Champ scientifique
- natural scienceschemical scienceselectrochemistryelectrolysis
- natural sciencesearth and related environmental sciencesgeologyvolcanology
- natural sciencesbiological sciencesbiochemistrybiomoleculeslipids
- natural scienceschemical sciencesorganic chemistryaliphatic compounds
- natural sciencesbiological sciencesmicrobiology
Appel à propositions
ERC-2010-StG_20091028
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Régime de financement
ERC-SG - ERC Starting GrantInstitution d’accueil
NE1 7RU Newcastle Upon Tyne
Royaume-Uni