Development of cellular magnetic dipoles in magnetotactic bacteria

Faivre, Damien ; Fischer, Anna ; Garcia Rubio, Ines ; Mastrogiacomo, Giovanni ; Gehring, Andreas

Resumen: Magnetotactic bacteria benefit from their ability to form cellular magnetic dipoles by assembling stable single-domain ferromagnetic particles in chains as a means to navigate along Earth's magnetic field lines on their way to favorable habitats. We studied the assembly of nanosized membrane-encapsulated magnetite particles (magnetosomes) by ferromagnetic resonance spectroscopy using Magnetospirillum gryphiswaldense cultured in a time-resolved experimental setting. The spectroscopic data show that 1), magnetic particle growth is not synchronized; 2), the increase in particle numbers is insufficient to build up cellular magnetic dipoles; and 3), dipoles of assembled magnetosome blocks occur when the first magnetite particles reach a stable single-domain state. These stable single-domain particles can act as magnetic docks to stabilize the remaining and/or newly nucleated superparamagnetic particles in their adjacencies. We postulate that docking is a key mechanism for building the functional cellular magnetic dipole, which in turn is required for magnetotaxis in bacteria.

Idioma: Inglés

DOI: 10.1016/j.bpj.2010.05.034

Año: 2010

Publicado en: BIOPHYSICAL JOURNAL 99, 4 (2010), 1268-1273
ISSN: 0006-3495

Factor impacto JCR: 4.218 (2010)

Categ. JCR: BIOPHYSICS rank: 18 / 72 = 0.25 (2010) - Q1 - T1

Tipo y forma: Artículo (Versión definitiva)