Crystal habits and magnetic microstructures of magnetosomes in coccoid magnetotactic bacteria

Crystal habits and magnetic microstructures of magnetosomes in coccoid magnetotactic bacteria.

We report on the application of off-axis electron holography and high-resolution TEM to study the crystal habits of magnetosomes and magnetic microstructure in two coccoid morphotypes of magnetotactic bacteria collected from a brackish lagoon at Itaipu, Brazil. Itaipu-1, the larger coccoid organism, contains two separated chains of unusually large magnetosomes; the magnetosome crystals have rou...

Magnetotactic bacteria and magnetosomes.

Habits of magnetosome crystals in coccoid magnetotactic bacteria.

High-resolution transmission electron microscopy and electron holography were used to study the habits of exceptionally large magnetite crystals in coccoid magnetotactic bacteria. In addition to the crystal habits, the crystallographic positioning of successive crystals in the magnetosome chain appears to be under strict biological control.

How magnetotactic bacteria make magnetosomes

Magnetotactic bacteria contain chains of magnetosomes that comprise a permanent magnetic dipole in each cell. In two separate, recent papers, Scheffel et a/. and Komeili et a/. describe the roles of the proteins MamJ and MamK in magnetosome chain formation. Here, we describe the two studies and highlight questions that must be addressed in future investigations of how magnetotactic bacteria con...

Formation of magnetosomes in magnetotactic bacteria.

The ability of magnetotactic bacteria to orient and migrate along geomagnetic field lines is based on intracellular magnetic structures, the magnetosomes, which comprise nano-sized, membrane bound crystals of magnetic iron minerals. The formation of magnetosomes is achieved by a biological mechanism that controls the accumulation of iron and the biomineralization of magnetic crystals with a cha...