Localized iron accumulation precedes nucleation and growth of magnetite crystals in magnetotactic bacteria - CEA - Commissariat à l’énergie atomique et aux énergies alternatives Access content directly
Journal Articles Scientific Reports Year : 2017

Localized iron accumulation precedes nucleation and growth of magnetite crystals in magnetotactic bacteria

Abstract

Many magnetotactic bacteria (MTB) biomineralize magnetite crystals that nucleate and grow inside intracellular membranous vesicles that originate from invaginations of the cytoplasmic membrane. The crystals together with their surrounding membranes are referred to magnetosomes. Magnetosome magnetite crystals nucleate and grow using iron transported inside the vesicle by specific proteins. Here we address the question: can iron transported inside MTB for the production of magnetite crystals be spatially mapped using electron microscopy? Cultured and uncultured MTB from brackish and freshwater lagoons were studied using analytical transmission electron microscopy in an attempt to answer this question. Scanning transmission electron microscopy was used at sub-nanometric resolution to determine the distribution of elements by implementing high sensitivity energy dispersive X-ray (EDS) mapping and electron energy loss spectroscopy (EELS). EDS mapping showed that magnetosomes are enmeshed in a magnetosomal matrix in which iron accumulates close to the magnetosome forming a continuous layer visually appearing as a corona. EELS, obtained at high spatial resolution, confirmed that iron was present close to and inside the lipid bilayer magnetosome membrane. This study provides important clues to magnetite formation in MTB through the discovery of a mechanism where iron ions accumulate prior to magnetite biomineralization.
Fichier principal
Vignette du fichier
41598_2017_Article_8994.pdf (2.75 Mo) Télécharger le fichier
Origin : Publisher files allowed on an open archive
Licence : CC BY - Attribution

Dates and versions

cea-02044699 , version 1 (09-02-2024)

Licence

Attribution

Identifiers

Cite

Jacques Werckmann, Jefferson Cypriano, Christopher T. Lefèvre, Kassiogé Dembélé, Ovidiu Ersen, et al.. Localized iron accumulation precedes nucleation and growth of magnetite crystals in magnetotactic bacteria. Scientific Reports, 2017, 7, pp.8291. ⟨10.1038/s41598-017-08994-9⟩. ⟨cea-02044699⟩
35 View
0 Download

Altmetric

Share

Gmail Facebook X LinkedIn More