title: Quantitative speciation of sulfur in bacterial sulfur globules: X-ray absorption spectroscopy reveals at least three different species of sulfur.
abstract: X-ray absorption near edge structure (XANES) spectroscopy at the sulfur K-edge was applied to probe the speciation of sulfur of metabolically different sulfur-accumulating bacteria in situ. Fitting the spectra using a least-square fitting routine XANES reveals at least three different forms of sulfur in bacterial sulfur globules. Cyclooctasulfur dominates in the sulfur globules of Beggiatoa alba and the very recently described giant bacterium Thiomargarita namibiensis. A second type of sulfur globules is present in Acidithiobacillus ferrooxidans: here the sulfur occurs as polythionates. In contrast, in purple and green sulfur bacteria the sulfur mainly consists of sulfur chains, irrespective of whether it is accumulated in globules inside or outside the cells. These results indicate that the speciation of sulfur in the sulfur globules reflects the different ecological and physiological properties of different metabolic groups of bacteria.
authors.affiliation: Institut für Mikrobiologie & Biotechnologie, Rheinische Friedrich-Wilhelms-Universität Bonn, Meckenheimer Allee 168, D-53115 Bonn, Germany1.
authors.forename: Alexander
authors.initials: A
authors.lastname: Prange
authors.affiliation: Physikalisches Institut, Rheinische Friedrich-Wilhelms-Universität Bonn, Nußallee 12, D-53115 Bonn, Germany2.
authors.forename: Reinhold
authors.initials: R
authors.lastname: Chauvistré
authors.affiliation: Physikalisches Institut, Rheinische Friedrich-Wilhelms-Universität Bonn, Nußallee 12, D-53115 Bonn, Germany2.
authors.forename: Hartwig
authors.initials: H
authors.lastname: Modrow
authors.affiliation: Physikalisches Institut, Rheinische Friedrich-Wilhelms-Universität Bonn, Nußallee 12, D-53115 Bonn, Germany2.
authors.forename: Josef
authors.initials: J
authors.lastname: Hormes
authors.affiliation: Institut für Mikrobiologie & Biotechnologie, Rheinische Friedrich-Wilhelms-Universität Bonn, Meckenheimer Allee 168, D-53115 Bonn, Germany1.
authors.forename: Hans G
authors.initials: HG
authors.lastname: Trüper
authors.affiliation: Institut für Mikrobiologie & Biotechnologie, Rheinische Friedrich-Wilhelms-Universität Bonn, Meckenheimer Allee 168, D-53115 Bonn, Germany1.
authors.forename: Christiane
authors.initials: C
authors.lastname: Dahl
mesh_terms: D015502:Absorptiometry, Photon; D020563:Gammaproteobacteria / Q000737:chemistry* / Q000254:growth & development / Q000378:metabolism; D010084:Oxidation-Reduction; D013455:Sulfur / Q000032:analysis* / Q000378:metabolism; D013885:Thiosulfates / Q000032:analysis
chemical_list: D013885:Thiosulfates; C026265:polythionates; C056471:cyclooctasulfur; D013455:Sulfur