Scientists isolate amazing magnetic bug

A new kind of magnetic bug could open the way to biotech and nanotech uses, which scientists have identified, isolated and successfully grown.

Last Updated: Dec 28, 2011, 16:12 PM IST

Washington: A new kind of magnetic bug could open the way to biotech and nanotech uses, which scientists have identified, isolated and successfully grown, reveals a study.

Magnetotactic bacteria are simple, single-cell organisms that are found in almost all water bodies. As their name implies, they orient and navigate along magnetic fields.

This is due to the nano-sized crystals of magnetic minerals magnetite or greigite they produce. They make their internal crystals, called magnetosomes, useful in drug delivery and medical imaging, the journal Science reported.

While many magnetite-producing bugs can be grown and easily studied, researcher Dennis Bazylinski and team from the University of Nevada, Las Vegas, were the first to cultivate a greigite-producing species. Greigite is an iron sulphide mineral, the equivalent of the iron oxide magnetite.
"Because greigite-producing bacteria have never been isolated, the crystals haven`t been tested for the types of biomedical and other applications that currently use magnetite," said Bazylinski, according to a university statement.

Researchers found the greigite-producing bacterium, called BW-1, in water samples collected more than 280 feet below sea level in Badwater basin, on the edge of Death Valley National Park in US.

Christopher Lefevre from the University of Aix-Marseille II, France, and Bazylinski later isolated and grew it leading to the discovery that BW-1 produces both greigite and magnetite.

A detailed look at its DNA revealed that BW-1 has two sets of magnetosome genes, unlike other such bacteria, which produce only one mineral and have only one set of magnetosome genes.
This suggests that the production of magnetite and greigite in BW-1 is likely controlled by separate sets of genes. That could be important in the mass production of either mineral for specific applications.

IANS