title: Discovery and Characterization of Iron Sulfide and Polyphosphate Bodies Coexisting in Archaeoglobus fulgidus Cells.
abstract: Inorganic storage granules have long been recognized in bacterial and eukaryotic cells but were only recently identified in archaeal cells. Here, we report the cellular organization and chemical compositions of storage granules in the Euryarchaeon, Archaeoglobus fulgidus strain VC16, a hyperthermophilic, anaerobic, and sulfate-reducing microorganism. Dense granules were apparent in A. fulgidus cells imaged by cryo electron microscopy (cryoEM) but not so by negative stain electron microscopy. Cryo electron tomography (cryoET) revealed that each cell contains one to several dense granules located near the cell membrane. Energy dispersive X-ray (EDX) spectroscopy and scanning transmission electron microscopy (STEM) show that, surprisingly, each cell contains not just one but often two types of granules with different elemental compositions. One type, named iron sulfide body (ISB), is composed mainly of the elements iron and sulfur plus copper; and the other one, called polyphosphate body (PPB), is composed of phosphorus and oxygen plus magnesium, calcium, and aluminum. PPBs are likely used for energy storage and/or metal sequestration/detoxification. ISBs could result from the reduction of sulfate to sulfide via anaerobic energy harvesting pathways and may be associated with energy and/or metal storage or detoxification. The exceptional ability of these archaeal cells to sequester different elements may have novel bioengineering applications.
authors.affiliation: Department of Microbiology, Immunology, and Molecular Genetics, UCLA, Los Angeles, CA 90095, USA; Electron Imaging Center for Nanomachines, California NanoSystems Institute, UCLA, Los Angeles, CA 90095, USA; The UCLA Biomedical Engineering Interdepartmental Program, UCLA, Los Angeles, CA 09905, USA.
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Toso
authors.affiliation: Department of Microbiology, Immunology, and Molecular Genetics, UCLA, Los Angeles, CA 90095, USA; Institute of Industrial Biotechnology, GC University, Lahore 54000, Pakistan.
authors.forename: Muhammad Mohsin
authors.initials: MM
authors.lastname: Javed
authors.affiliation: Department of Microbiology, Immunology, and Molecular Genetics, UCLA, Los Angeles, CA 90095, USA.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Czornyj
authors.affiliation: Department of Microbiology, Immunology, and Molecular Genetics, UCLA, Los Angeles, CA 90095, USA; The UCLA-DOE Institute of Genomics and Proteomics, UCLA, Los Angeles, CA 90095, USA.
authors.forename: Robert P
authors.identifier: 0000-0002-1937-8412
authors.initials: RP
authors.lastname: Gunsalus
authors.affiliation: Department of Microbiology, Immunology, and Molecular Genetics, UCLA, Los Angeles, CA 90095, USA; Electron Imaging Center for Nanomachines, California NanoSystems Institute, UCLA, Los Angeles, CA 90095, USA; The UCLA Biomedical Engineering Interdepartmental Program, UCLA, Los Angeles, CA 09905, USA.
authors.forename: Z Hong
authors.initials: ZH
authors.lastname: Zhou
mesh_terms: D000332:Aerobiosis; D000693:Anaerobiosis; D019611:Archaeoglobus fulgidus / Q000737:chemistry* / Q000648:ultrastructure; D020285:Cryoelectron Microscopy; D003594:Cytoplasmic Granules / Q000737:chemistry* / Q000648:ultrastructure; D055032:Electron Microscope Tomography; D058085:Iron Compounds / Q000032:analysis*; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D011122:Polyphosphates / Q000032:analysis*; D013052:Spectrometry, X-Ray Emission; D013440:Sulfides / Q000032:analysis*
chemical_list: D058085:Iron Compounds; D011122:Polyphosphates; D013440:Sulfides