Magnetotactic bacteria

Bacteria that orient along magnetic fields

Magnetotactic bacteria (MTB) are a diverse group of bacteria that orient themselves along the magnetic field lines of Earth's magnetic field. They are found in aquatic environments, both marine and freshwater, and are known for their unique ability to navigate using magnetism. This ability is due to the presence of intracellular structures called magnetosomes, which contain magnetic mineral crystals.

Characteristics

Magnetotactic bacteria are typically microaerophilic, meaning they thrive in environments with low oxygen concentrations. They are motile and use flagella to move through their aquatic habitats. The magnetosomes within these bacteria are composed of either magnetite (Fe₃O₄) or greigite (Fe₃S₄), which are magnetic minerals that allow the bacteria to align with magnetic fields.

Magnetosomes

MTB polarities in Magnetotactic bacteria

Magnetosomes are membrane-bound organelles that contain magnetic mineral crystals. These structures are arranged in chains within the bacterial cell, acting like a compass needle to orient the bacteria along magnetic field lines. The formation of magnetosomes is a highly controlled biomineralization process, involving specific proteins that regulate the size, shape, and composition of the magnetic crystals.

Ecological Role

Magnetotactic bacteria play a significant role in the biogeochemical cycling of iron and sulfur in aquatic environments. By orienting along magnetic field lines, they can efficiently navigate to optimal zones within the water column where conditions are favorable for their growth and survival. This behavior is particularly important in stratified water bodies where oxygen and nutrient gradients exist.

Applications

The unique properties of magnetotactic bacteria and their magnetosomes have potential applications in various fields, including biotechnology and nanotechnology. For example, magnetosomes can be used in the development of magnetic nanoparticles for medical imaging, drug delivery, and environmental remediation.

Related pages

• Biomineralization
• Magnetosome
• Microaerophilic organism