SREL Reprint #2743
Crystal morphology of MV-1 magnetite
Simon J. Clemett1, Kathie L. Thomas-Keprta1, Joel Shimmin2, Mary Morphew2, J. Richard McIntosh2, Dennis A. Bazylinski3, Joseph L. Kirschvink4, Susan J. Wentworth1, David S. McKay5, Hojatollah Vali6, Everett K. Gibson, Jr.5, and Christopher S. Romanek1
1Lockheed Martin Space Operations (NASA/Johnson Space Center Astrobilogy Institute),
2400 NASA Road 1, Mail Code C23, Houston, Texas 77058, USA
2Department of Molecular, Cellular & Developmental Biology, University of Colorado,
Boulder, Colorado 80309, USA
3Iowa State University, Department of Microbiology, 207 Science I, Ames, Iowa 50011, USA
4California Institute of Technology, Division of Geological and Planetary Sciences,
1200 East California Boulevard, Pasadena, California 91125, USA
5NASA, Johnson Space Center, Houston, Texas 77058, USA
6McGill University, Department of Earth and Planetary Sciences, 3450 University Street,
Montreal, PQ H3A 2A7, Canada
7Savannah River Ecology Laboratory, Drawer E, University of Georgia, Aiken, South Carolina 29802, USA
Abstract: Intracellular magnetite (Fe304) crystals produced by magnetotactic bacteria strain MV-1 are in the single-domain size range, and are chemically pure. We have previously suggested that they exhibit an unusual crystal habit described as truncated hexa-octahedral. Such a crystal morphology has not been demonstrated for any inorganic population of magnetite, nor would it be expected, given considerations of symmetry and free energy. By inference, this morphology is a physical signature of a biological origin. Here we report data from transmission electron microscope (TEM) tomography of such crystals isolated from magnetotactic bacteria, which confirm the unusual geometry, originally proposed from classical TEM tilt imaging.
SREL Reprint #2743
Clemett, S. J., K. L. Thomas-Keprta, J. Shimmin, M. Morphew, J. R. McIntosh, D. A. Bazylinski, J. L. Kirschvink, S. J. Wentworth, D. S. McKay, H. Vali, E. K. Gibson, Jr., and C. S. Romanek. 2002. Crystal morphology of MV-1 magnetite. American Mineralogist 87:1727-1730.
This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).