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Biogeochemical Activity of Siderophilic Cyanobacteria and Insights from their Genomes Implications for the Development of New BiosignaturesVerifying the links between genomie features in living organisms and their mineralization/demineralization activity will help to reveal traces of life on Earth and beyond. Among contemporary environments, iron-depositing hot springs (IDHS) may represent one of the most appropriate natural models for insights into ancient life since organisms may have originated on Earth and possibly Mars in association with hydrothennal activity and high [Fe(2+)]. Siderophilic or "iron-loving" cyanobacteria (CB) inhabiting IDHS may have genomic features and properties similar to those of ancient organisms because abundant Fe(2+) in IDHS has a strong potential to increase the magnitude of oxidative stress. That is why specific and/or additional proteins involved in Fe mineralization by siderophilic CB are expected. Inorganic polyphosphates (PPi) are known to increase the viability of prokaryotes Linder heavy metal concentrations and UV stress conditions. PPi have also been proposed as biosignatures. Ancient CB could have also been stressed by occasional migrations from the Fe(2+) rich Ocean to the basaltic land which was almost devoid of dissolved Fe(2+). Thus, the study of the adaptation reactions of siderophilic CB to fluctuation of dissolved Fe level may shed light on the paleophysiology of ancient oxygenic prokaryotes. Moreover, bioweathered Fe, Al, P, Cu, Ti and rare earth elements can be thought of as candidate organomarkers that document the effects of or ganic molecules in weathered rocks. However, the molecular mechanisms of the maintenance of Fe homeostasis in siderophilic CB, the role of PPi for this process and bioweathering activities are poorly understood. Here we present preliminary results describing a new mechanism of Fe mineralization in siderophilic CB, the effect of Fe on the generation of PPi bodies in siderophilic CB, their bioweathering activity and preliminary analysis of the diversity of proteins involved in the prevention of oxidative stress in phototrophs inhabiting IDHS.
Document ID
20100005631
Acquisition Source
Johnson Space Center
Document Type
Conference Paper
Authors
Brown, I. I.
(Jacobs Technologies Engineering Science Contract Group Houston, TX, United States)
Bryant, D. A.
(Pennsylvania State Univ. University Park, PA, United States)
Thomas,-Keprta, K. L.
(Jacobs Technologies Engineering Science Contract Group Houston, TX, United States)
Tringe, S. G.
(Department of Energy United States)
Sarkisova, S. A.
(Jacobs Technologies Engineering Science Contract Group Houston, TX, United States)
Galindo, C., Jr.
(Jacobs Technologies Engineering Science Contract Group Houston, TX, United States)
Malley, K.
(Universities Space Research Association United States)
Sosa, O.
(Universities Space Research Association United States)
Garrison, D. H.
(Jacobs Technologies Engineering Science Contract Group Houston, TX, United States)
McKay, David S.
(NASA Johnson Space Center Houston, TX, United States)
Date Acquired
August 25, 2013
Publication Date
January 1, 2010
Subject Category
Geosciences (General)
Report/Patent Number
JSC-CN-19615
Meeting Information
Meeting: Lunar and Planetary Science Conference
Location: The Woodlands, TX
Country: United States
Start Date: March 1, 2010
End Date: March 5, 2010
Sponsors: NASA Headquarters, Lunar and Planetary Inst.
Distribution Limits
Public
Copyright
Public Use Permitted.
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