A new group of bacteria has been discovered in Death Valley’s Badwater Basin that makes nanoparticles of both magnetite (Fe3O4) and greigite (Fe3S4). Magnetotactic bacteria use these tiny magnets as part of their navigation system to align themselves along the Earth’s magnetic field. Typical magnetotactic bacteria do not make both magnetite and greigite and the discovery dispels the notion that greigite-producing bacteria live only in marine environments. The researchers found two different gene clusters related to magnet formation, suggesting that one is responsible for making magnetite and the other greigite. The discovery will help provide insight on the chemical conditions under which greigite is formed, which could be important for figuring out how to mass produce this kind of magnetic nanocrystal for nano- and biotechnology applications.
C. T. Lefèvre, N. Menguy, F. Abreu, U. Lins, M. Pósfai, T. Prozorov, D. Pignol, R. B. Frankel, and D. A. Bazylinski, “A Cultured Greigite-Producing Magnetotactic Bacterium in a Novel Group of Sulfate-Reducing Bacteria”, Science, 2011, 334, 1720-1723. DOI 10.1126/science.1212596