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Alternative origins for nannobacteria-like objects in calcite

1999; Geological Society of America; Volume: 27; Issue: 4 Linguagem: Inglês

10.1130/0091-7613(1999)027 2.3.co;2

1943-2682

Brenda L. Kirkland, F. Leo Lynch, Michael Rahnis, Robert L. Folk, Ian J. Molineux, Robert McLean,

Geological formations and processes

Research Article| April 01, 1999 Alternative origins for nannobacteria-like objects in calcite Brenda L. Kirkland; Brenda L. Kirkland 1Department of Geological Sciences, University of Texas, Austin, Texas 78712, USA Search for other works by this author on: GSW Google Scholar F. Leo Lynch; F. Leo Lynch 1Department of Geological Sciences, University of Texas, Austin, Texas 78712, USA Search for other works by this author on: GSW Google Scholar Michael A. Rahnis; Michael A. Rahnis 1Department of Geological Sciences, University of Texas, Austin, Texas 78712, USA Search for other works by this author on: GSW Google Scholar Robert L. Folk; Robert L. Folk 1Department of Geological Sciences, University of Texas, Austin, Texas 78712, USA Search for other works by this author on: GSW Google Scholar Ian J. Molineux; Ian J. Molineux 2Department of Microbiology, University of Texas, Austin, Texas 78712, USA Search for other works by this author on: GSW Google Scholar Robert J. C. McLean Robert J. C. McLean 3Department of Biology, Southwest Texas State University, San Marcos, Texas 78666, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Brenda L. Kirkland 1Department of Geological Sciences, University of Texas, Austin, Texas 78712, USA F. Leo Lynch 1Department of Geological Sciences, University of Texas, Austin, Texas 78712, USA Michael A. Rahnis 1Department of Geological Sciences, University of Texas, Austin, Texas 78712, USA Robert L. Folk 1Department of Geological Sciences, University of Texas, Austin, Texas 78712, USA Ian J. Molineux 2Department of Microbiology, University of Texas, Austin, Texas 78712, USA Robert J. C. McLean 3Department of Biology, Southwest Texas State University, San Marcos, Texas 78666, USA Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1999) 27 (4): 347–350. https://doi.org/10.1130/0091-7613(1999)027 2.3.CO;2 Article history First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Brenda L. Kirkland, F. Leo Lynch, Michael A. Rahnis, Robert L. Folk, Ian J. Molineux, Robert J. C. McLean; Alternative origins for nannobacteria-like objects in calcite. Geology 1999;; 27 (4): 347–350. doi: https://doi.org/10.1130/0091-7613(1999)027 2.3.CO;2 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 SocietyGeology Search Advanced Search Abstract More than 40 calcite-precipitation experiments were performed under sterile conditions in order to investigate the origins of 25–300 nm spherical-, rod-, and ovoid-shaped objects that have been widely interpreted as evidence of nanometer-scale life (i.e., nannobacteria). Individual experiments included the addition of soluble organic compounds, common species of eubacteria, or phage-induced eubacterial lysates. These experiments indicate that many of the nanometer-scale objects have inorganic or nonnannobacterial origins. In the precipitation experiments, calcite formed euhedral crystals 50–800 nm in diameter and smaller (<50 nm) anhedral or rounded particles or protocrystals. The small anhedral or rounded solids resembled nannobacteria. The relative amount of anhedral or rounded calcite was greatest in experiments with a dissolved organic component. These controlled experiments are in accord with observations that rounded nanometer-scale objects are more common in minerals formed in organic-rich environments. Bacterial fragments occur as rounded to irregularly shaped particles that included cell-wall fragments, expulsed cytoplasm, and relict capsules that also closely resembled nannobacteria. Acid etching of the large euhedral crystals produced in the precipitation experiments also resulted in the formation of nanometer-scale features that resembled nannobacteria in natural carbonates. The shapes of the etching artifacts vary as a function of the strength of the acid and the duration of etching. Much caution is advisable in interpreting the origin of rounded features <50 nm. 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.