Environmental parameters affect the physical properties of fast-growing magnetosomes
  • Metaadatok
Tartalom: http://dx.doi.org/10.2138/am.2008.2678
Archívum: MTA Könyvtár
Gyűjtemény: Status = Published



Type = Article
Cím:
Environmental parameters affect the physical properties of fast-growing magnetosomes
Létrehozó:
Faivre, D.
Menguy, N.
Pósfai, Mihály
Schuler, Dezső
Kiadó:
Mineralogical Society of America
Dátum:
2008
Téma:
QD06 Mineralogy / ásványtan
QE01 Geophysics / geofizika
QE02 Geochemistry / geokémia
Tartalmi leírás:
Magnetotactic bacteria are known to mediate the formation of intracellular magnetic nanoparticles
in organelles called magnetosomes. These magnetite crystals are formed through a process called
biologically controlled mineralization, in which the microorganisms exert a strict control over the
formation and development of the mineral phase. By inducing magnetite nucleation and growth in
resting, Fe-starved cells of Magnetospirillum gryphiswaldense, we have followed the dynamics of
magnetosome development. By studying the properties of the crystals at several steps of maturity,
we observed that freshly induced particles lacked a well-defined morphology. More surprisingly,
although the mean particle size of mature magnetosomes is similar to that of magnetosomes formed
by constantly growing and Fe-supplemented bacteria, we found that other physical properties such
as crystal-size distribution, aspect ratio, and morphology significantly differ. Correlating these results
with measurements of Fe uptake rates, we suggest that the expression of different faces is favored for
different growth conditions. These results imply that the biological control over magnetite biominer-
alization by magnetotactic bacteria can be disturbed by environmental parameters. Specifically, the
morphology of magnetite crystals is not exclusively determined by biological intervention through
vectorial regulation at the organic boundaries or by molecular interaction with the magnetosome
membrane, but also by the rates of Fe uptake. This insight may contribute to better define biomarkers
and to an improved understanding of biomineralizing systems.
Típus:
Article
PeerReviewed
Formátum:
text
Azonosító:
Faivre, D. and Menguy, N. and Pósfai, Mihály and Schuler, Dezső (2008) Environmental parameters affect the physical properties of fast-growing magnetosomes. American Mineralogist, 93 (2-3). pp. 463-469. ISSN 0003-004X
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