Magnetic fingerprint in marine sediments: clues from cultivated Magnetovibrio blakemorei and recent cores from Brazilian Coast
Abstract
The magnetic properties (first order reversal curves, ferromagnetic resonance and decomposition of saturation remanent magnetization acquisition) of Magnetovibrio blakemorei strain MV-1, a marine magnetotactic bacterium, differ from those of other magnetotactic species from sediments deposited in lakes and marine habitats previously studied. This finding suggests that magnetite produced by some magnetotactic bacteria retains magnetic properties in relation to the crystallographic structure of the magnetic phase produced and thus might represent a 'magnetic fingerprint' for a specific magnetotactic bacterium. The technique used to determine this fingerprint is a non-destructive, new technology that might allow for the identification and presence of specific species or types of magnetotactic bacteria in certain environments such as sediment. We also show some preliminary results on the biogeochemical factors that control magnetotactic bacterial populations, documenting the environment and the preservation of bacterial magnetite, which dominates the palaeomagnetic signal throughout recent sediments from Brazilian Coast. We searched for magnetotactic bacteria in order to understand the ecosystems and environmental change related to their presence in sediments. We focused on studying the environmental conditions that allow for the presence of magnetotactic bacteria and magnetosomes in sediments including determining magnetotactic bacterial populations in marine settings, measuring crucial nutrient availability in the water column and in sediments, and examining particulate delivery to the seafloor.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2013
- Bibcode:
- 2013AGUFMGP53B1134J
- Keywords:
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- 0419 BIOGEOSCIENCES Biomineralization;
- 0463 BIOGEOSCIENCES Microbe/mineral interactions;
- 1540 GEOMAGNETISM AND PALEOMAGNETISM Rock and mineral magnetism;
- 4840 OCEANOGRAPHY: BIOLOGICAL AND CHEMICAL Microbiology and microbial ecology