Skip to Main Content
Skip Nav Destination
GEOREF RECORD

Continuous time-resolved X-ray diffraction of the biocatalyzed reduction of Mn oxide

Timothy B. Fischer, Peter J. Heaney, Je-Hun Jang, Daniel E. Ross, Susan L. Brantley, Jeffrey E. Post and Ming Tien
Continuous time-resolved X-ray diffraction of the biocatalyzed reduction of Mn oxide
American Mineralogist (November 2008) 93 (11-12): 1929-1932

Abstract

Here we report the first continuous time-resolved X-ray diffraction analysis of a biologically mediated mineral reaction. We incubated total membrane (TM) fractions of the facultative anaerobe Shewanella oneidensis in an anoxic environmental reaction cell with formate (as electron donor via formate dehydrogenase) and powdered birnessite, a layered Mn (super 3+,4+) oxide common to many soils. Using both synchrotron and conventional X-ray sources, we irradiated the reaction mixtures for up to two weeks and observed bioreduction and dissolution of birnessite and the concomitant precipitation of rhodochrosite [Mn (super 2+) CO (sub 3) ] and hausmannite [Mn (super 2+) Mn (sub 2) (super 3+) O (sub 4) ]. The high time resolution of these experiments documented systematic changes in crystal structure during the breakdown of birnessite and the emergence of nanocarystalline rhodochrosite. In addition, the relative abundances of birnessite and rhodochrosite were quantified over time for different concentrations of TM fraction, allowing for the determination of rate equations that govern this bioreaction. Importantly, constant irradiation for two weeks did not stop the enzymatic reaction, suggesting that enzymes may be more resilient than whole cells when exposed to X-ray radiation.


ISSN: 0003-004X
EISSN: 1945-3027
Coden: AMMIAY
Serial Title: American Mineralogist
Serial Volume: 93
Serial Issue: 11-12
Title: Continuous time-resolved X-ray diffraction of the biocatalyzed reduction of Mn oxide
Affiliation: Pennsylvania State University, Department of Geosciences, University Park, PA, United States
Pages: 1929-1932
Published: 200811
Text Language: English
Publisher: Mineralogical Society of America, Washington, DC, United States
References: 19
Accession Number: 2009-010637
Categories: Mineralogy of non-silicates
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus.
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Abstract, copyright, Mineralogical Society of America. Reference includes data from GeoScienceWorld, Alexandria, VA, United States
Update Code: 200906
Close Modal

or Create an Account

Close Modal
Close Modal