Unexpected extracellular and intracellular sulfur species during growth of Allochromatium vinosum with reduced sulfur compounds.
Before its uptake and oxidation by purple sulfur bacteria, elemental sulfur probably first has to be mobilized. To obtain more insight into this mobilization process in the phototrophic purple sulfur bacterium Allochromatium vinosum, we used HPLC analysis and X-ray absorption near-edge structure (XANES) spectroscopy for the detection and identification of sulfur compounds in culture supernatants and bacterial cells. We intended to identify soluble sulfur compounds that specifically occur during growth on elemental sulfur, and therefore compared spectra of cultures grown on sulfur with those of cultures grown on sulfide or thiosulfate. While various unexpected oxidized organic sulfur species (sulfones, C-SO(2)-C, and sulfonates, C-SO(3)(-)) were observed via XANES spectroscopy in the supernatants, we obtained evidence for the presence of monosulfane sulfonic acids inside the bacterial cells by HPLC analysis. The concentrations of the latter compounds showed a tight correlation with the content of intracellular sulfur, reaching their maximum when sulfur began to be oxidized. None of the detected sulfur compounds appeared to be a specific soluble intermediate or product of elemental sulfur mobilization. It therefore seems unlikely that mobilization of elemental sulfur by purple sulfur bacteria involves excretion of soluble sulfur-containing substances that would be able to act on substrate distant from the cells.
Rheinische Friedrich-Wilhelms-Universität Bonn, Institut für Mikrobiologie & Biotechnologie, Meckenheimer Allee 168, 53115 Bonn, Germany.|Hochschule Niederrhein, Mikrobiologie und Lebensmittelhygiene, Rheydter Straße 277, 41065 Mönchengladbach, Germany.
Bettina
B
Franz
Rheinische Friedrich-Wilhelms-Universität Bonn, Institut für Mikrobiologie & Biotechnologie, Meckenheimer Allee 168, 53115 Bonn, Germany.
Thomas
T
Gehrke
Louisiana State University, The J. Bennett Johnston, Sr Center for Advanced Microstructures and Devices (CAMD), 6980 Jefferson Highway, Baton Rouge, LA 70806, USA.|Hochschule Niederrhein, Mikrobiologie und Lebensmittelhygiene, Rheydter Straße 277, 41065 Mönchengladbach, Germany.
Henning
H
Lichtenberg
University of Saskatchewan, Canadian Light Source Inc. (CLS), 101 Perimeter Road, Saskatoon, SK S7N 0X4, Canada.|Louisiana State University, The J. Bennett Johnston, Sr Center for Advanced Microstructures and Devices (CAMD), 6980 Jefferson Highway, Baton Rouge, LA 70806, USA.
Josef
J
Hormes
Rheinische Friedrich-Wilhelms-Universität Bonn, Institut für Mikrobiologie & Biotechnologie, Meckenheimer Allee 168, 53115 Bonn, Germany.
Christiane
C
Dahl
Louisiana State University, The J. Bennett Johnston, Sr Center for Advanced Microstructures and Devices (CAMD), 6980 Jefferson Highway, Baton Rouge, LA 70806, USA.|Hochschule Niederrhein, Mikrobiologie und Lebensmittelhygiene, Rheydter Straße 277, 41065 Mönchengladbach, Germany.
Alexander
A
Prange
D002844:Chromatium / Q000737:chemistry* / Q000254:growth & development / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D003470:Culture Media / Q000737:chemistry; D005110:Extracellular Space / Q000737:chemistry*; D042541:Intracellular Space / Q000737:chemistry*; D019897:Periplasm / Q000737:chemistry / Q000378:metabolism; D013057:Spectrum Analysis; D013440:Sulfides / Q000737:chemistry / Q000378:metabolism; D013450:Sulfones / Q000737:chemistry / Q000378:metabolism; D013451:Sulfonic Acids / Q000737:chemistry / Q000378:metabolism; D013455:Sulfur / Q000737:chemistry / Q000378:metabolism*; D013885:Thiosulfates / Q000737:chemistry / Q000378:metabolism
D003470:Culture Media; D013440:Sulfides; D013450:Sulfones; D013451:Sulfonic Acids; D013885:Thiosulfates; D013455:Sulfur