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Title: X-Ray Absorption Spectroscopy As a Probe of Microbial Sulfur Biochemistry: the Nature of Bacterial Sulfur Globules Revisited

Abstract

The chemical nature of the sulfur in bacterial sulfur globules has been the subject of controversy for a number of years. Sulfur K-edge X-ray absorption spectroscopy (XAS) is a powerful technique for probing the chemical forms of sulfur in situ, but two groups have used it with very different conclusions. The root of the controversy lies with the different detection strategies used by the two groups, which result in very different spectra. This paper seeks to resolve the controversy. We experimentally demonstrate that the use of transmittance detection for sulfur K-edge XAS measurements is highly prone to spectroscopic distortions and that much of the published work on sulfur bacteria is very likely based on distorted data. We also demonstrate that all three detection methods used for X-ray absorption experiments yield essentially identical spectra when the measurements are carried out under conditions where no experimental distortions are expected. Finally, we turn to the original question--the chemical nature of bacterial sulfur. We examine isolated sulfur globules of Allochromatium vinosum and intact cells of a strain of magnetotactic coccus and show that XAS indicates the presence of a chemical form of sulfur resembling S{sub 8}.

Authors:
; ; ; ;
Publication Date:
Research Org.:
Stanford Linear Accelerator Center (SLAC)
Sponsoring Org.:
USDOE
OSTI Identifier:
953158
Report Number(s):
SLAC-REPRINT-2009-126
Journal ID: ISSN 0021-9193; JOBAAY; TRN: US200914%%210
DOE Contract Number:  
AC02-76SF00515
Resource Type:
Journal Article
Resource Relation:
Journal Name: J. Bacteriol. 190:6376,2008; Journal Volume: 190; Journal Issue: 19
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; ABSORPTION SPECTROSCOPY; X-RAY SPECTROSCOPY; BACTERIA; BIOCHEMISTRY; DETECTION; SULFUR; CHEMICAL STATE; Other,BIO, CHEM

Citation Formats

George, G.N., Gnida, M., Bazylinski, D.A., Prince, R.C., and Pickering, I.J.. X-Ray Absorption Spectroscopy As a Probe of Microbial Sulfur Biochemistry: the Nature of Bacterial Sulfur Globules Revisited. United States: N. p., 2009. Web.
George, G.N., Gnida, M., Bazylinski, D.A., Prince, R.C., & Pickering, I.J.. X-Ray Absorption Spectroscopy As a Probe of Microbial Sulfur Biochemistry: the Nature of Bacterial Sulfur Globules Revisited. United States.
George, G.N., Gnida, M., Bazylinski, D.A., Prince, R.C., and Pickering, I.J.. Mon . "X-Ray Absorption Spectroscopy As a Probe of Microbial Sulfur Biochemistry: the Nature of Bacterial Sulfur Globules Revisited". United States.
@article{osti_953158,
title = {X-Ray Absorption Spectroscopy As a Probe of Microbial Sulfur Biochemistry: the Nature of Bacterial Sulfur Globules Revisited},
author = {George, G.N. and Gnida, M. and Bazylinski, D.A. and Prince, R.C. and Pickering, I.J.},
abstractNote = {The chemical nature of the sulfur in bacterial sulfur globules has been the subject of controversy for a number of years. Sulfur K-edge X-ray absorption spectroscopy (XAS) is a powerful technique for probing the chemical forms of sulfur in situ, but two groups have used it with very different conclusions. The root of the controversy lies with the different detection strategies used by the two groups, which result in very different spectra. This paper seeks to resolve the controversy. We experimentally demonstrate that the use of transmittance detection for sulfur K-edge XAS measurements is highly prone to spectroscopic distortions and that much of the published work on sulfur bacteria is very likely based on distorted data. We also demonstrate that all three detection methods used for X-ray absorption experiments yield essentially identical spectra when the measurements are carried out under conditions where no experimental distortions are expected. Finally, we turn to the original question--the chemical nature of bacterial sulfur. We examine isolated sulfur globules of Allochromatium vinosum and intact cells of a strain of magnetotactic coccus and show that XAS indicates the presence of a chemical form of sulfur resembling S{sub 8}.},
doi = {},
journal = {J. Bacteriol. 190:6376,2008},
number = 19,
volume = 190,
place = {United States},
year = {Mon May 18 00:00:00 EDT 2009},
month = {Mon May 18 00:00:00 EDT 2009}
}