What Is Magnetotactic Bacteria?
In 1963, at the University of Pavia in Lombardy, Italy, Salvatore Bellini was observing bog sediments under his microscope. As opposed to the normal movement, Bellini noticed a group of bacteria orienting themselves in a unique direction. Upon further study, he realized that these peculiar microorganisms were moving in the direction of the North Pole. He dubbed them “magnetosensitive bacteria.”
Despite the Italian scientist’s early observation, the first peer-reviewed article on the bacteria didn’t appear until 1975, when microbiologist Richard P. Blakemore had a similar observation of certain bacteria that were capable of orienting themselves in an odd way. Blakemore came to realize that the microorganisms were following the direction of Earth’s magnetic field, from south to north. He renamed the organisms “magnetotactic.”
What is Magnetotactic Bacteria?
These bacteria have caused much speculation over the years — they even took a journey on a space shuttle when scientists decided to examine their magnetotactic properties in the absence of gravity. But what creates the magnetosensitivity in these strange microorganisms?
It primarily arises from the fact that they create crystal chains of magnetic minerals within their own cells, usually either magnetite or greigite. As opposed to the magnetoception of animals, like birds who can detect magnetic fields for navigational purposes, these bacteria contain actual magnetic particles that force the bacteria into alignment with the poles. This was proved by the fact that even dead cells align.
Despite the fact that they are quite talented dancers, these bacteria may not fascinate everyone. But their talents may go far beyond simple biological magnetism. The magnetite particles that they precipitate actually offer many advantages to chemically synthesized magnetite. Their cells have also been used to determine the magnetic poles in meteorites and other rocks.
The crystals have also been used in studies of magnetic domain analysis and in many helpful medical situations, for example forming magnetic antibodies, detecting and removing E. coli cells, and even introducing genes into cells.
There is still much testing that needs to be done before these bacteria can be used commercially, but maybe someday they can dance their way into performing medical miracles for humanity.