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The occurrence of the mycotoxins deoxynivalenol (DON) and ochratoxin A (OTA) in the winter wheat of 1997 and 1998 grown under organic farming conditions was investigated using ELISAs (R-Biopharm) for quantification. The influence of delayed drying of the grain after harvest on the development of DON and OTA was determined in storage trials (moisture: 17%(More)
LbL nano self-assembly coating of A. vinosum with different polyelectrolyte combinations is presented as an example to investigate substrate uptake in bacteria. The effects of surface charge and the formation of a physical barrier provides new insights in the contact mechanisms between the cell surface and insoluble elemental sulfur. Furthermore, uptake of(More)
The chemical environment of lead in roots and leaves of plants from four different plant families and a lichen from a former lead mining site in the Eifel Mountains in Germany was determined by Pb L3-edge XANES measurements using solid reference compounds and also aqueous solutions of different ionic strength simulating the plant environment. Pb(2+) ions in(More)
The purple sulfur bacterium Allochromatium vinosum can use elemental sulfur as an electron donor for anoxygenic photosynthesis. The elemental sulfur is taken up, transformed into intracellular sulfur globules and oxidized to sulfate. Commercially available "elemental" sulfur usually consists of the two species cyclo-octasulfur and polymeric sulfur. The(More)
The Firmicutes Thermoanaerobacter sulfurigignens and Thermoanaerobacterium thermosulfurigenes convert thiosulfate, forming sulfur globules inside and outside cells. X-ray absorption near-edge structure analysis revealed that the sulfur consisted mainly of sulfur chains with organic end groups similar to sulfur formed in purple sulfur bacteria, suggesting(More)
During the oxidation of sulfide and thiosulfate purple and green sulfur bacteria accumulate globules of 'elemental' sulfur. Although essential for a thorough understanding of sulfur metabolism in these organisms, the exact chemical nature of the stored sulfur is still unclear. We applied sulfur K-edge X-ray absorption near edge spectroscopy (XANES) to probe(More)
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(More)
Silver ions are widely used as antibacterial agents, but the basic molecular mechanism of this effect is still poorly understood. X-ray absorption near-edge structure (XANES) spectroscopy at the Ag LIII, S K, and P K edges reveals the chemical forms of silver in Staphylococcus aureus and Escherichia coli (Ag(+) treated). The Ag LIII-edge XANES spectra of(More)
Two anaerobic thermophilic bacteria, designated strains JW/SL824 and JW/SL-NZ826(T), were isolated from an acidic volcanic steam outlet on White Island, New Zealand. Cells were rod-shaped, spore-forming, motile and Gram-stain negative, but contained Gram-type positive cell wall. Strain JW/SL-NZ826(T) utilized various carbohydrates including xylose and(More)