Iron sulfides from magnetotactic bacteria; structure, composition, and phase transitions

Abstract

Other| December 01, 1998 Iron sulfides from magnetotactic bacteria; structure, composition, and phase transitions Mihaly Posfai; Mihaly Posfai Arizona State Universty, Departments of Geology and Chemistry/Biochemistry, Tempe, AZ, United States Search for other works by this author on: GSW Google Scholar Peter R. Buseck; Peter R. Buseck Search for other works by this author on: GSW Google Scholar Dennis A. Bazylinski; Dennis A. Bazylinski Search for other works by this author on: GSW Google Scholar Richard B. Frankel Richard B. Frankel Search for other works by this author on: GSW Google Scholar Author and Article Information Mihaly Posfai Arizona State Universty, Departments of Geology and Chemistry/Biochemistry, Tempe, AZ, United States Peter R. Buseck Dennis A. Bazylinski Richard B. Frankel Publisher: Mineralogical Society of America First Online: 02 Mar 2017 Online ISSN: 1945-3027 Print ISSN: 0003-004X GeoRef, Copyright 2004, American Geological Institute. American Mineralogist (1998) 83 (11-12_Part_2): 1469–1481. https://doi.org/10.2138/am-1998-11-1235 Article history First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Mihaly Posfai, Peter R. Buseck, Dennis A. Bazylinski, Richard B. Frankel; Iron sulfides from magnetotactic bacteria; structure, composition, and phase transitions. American Mineralogist 1998;; 83 (11-12_Part_2): 1469–1481. doi: https://doi.org/10.2138/am-1998-11-1235 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyAmerican Mineralogist Search Advanced Search Abstract Using transmission electron microscopy, we studied the structures and compositions of Fe sulfides within cells of magnetotactic bacteria that were collected from natural habitats. Ferrimagnetic greigite (Fe 3 S 4 ) occurred in all types of sulfide-producing magnetotactic bacteria examined. Mackinawite (tetragonal FeS) and, tentatively, sphalerite-type cubic FeS were also identified. In contrast to earlier reports, we did not find pyrite (FeS 2 ) or pyrrhotite (Fe (sub 1-x) S). Mackinawite converted to greigite over time within the bacteria that were deposited on electron microscope grids and stored in air. Orientation relationships between the two minerals indicate that the cubic-close-packed S substructure remains unchanged during the transformation; only the Fe atoms rearrange. Neither mackinawite nor cubic FeS are magnetic, and yet they are aligned in chains such that when converted to magnetic greigite, the probable easy axis of magnetization, [100], is parallel to the chain direction. The resulting chains of greigite are ultimately responsible for the magnetic dipole moment of the cell. Both greigite and mackinawite magnetosomes can contain Cu, depending on the sampling locality. Because bacterial mackinawite and cubic FeS are unstable over time, only greigite crystals are potentially useful as geological biomarkers. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.