333 research outputs found

    A biochemical study of colloidal sulfur.

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    Improved cyanolysis protocol for detection of zero-valent sulfur in natural aquatic systems

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    We propose a novel protocol for detection of reactive zero‐valent sulfur (ZVS) in natural aquatic samples including seawater. Reaction with hot potassium cyanide at slightly acidic conditions recovers ZVS from colloidal fraction of particulate elemental sulfur, polysulfides (Sn2−), and their protonated forms. Preconcentration by partial evaporation of the sample and separation of thiocyanate anions by high‐performance liquid chromatography on the C30 reverse phase column modified with poly(ethylene glycol) followed by spectrophotometric detection at 220 nm wavelength allows us to detect reactive ZVS with detection limit of 3 nmol L−1 for fresh water samples and 6 nmol L−1 for seawater samples. Storage at 4°C for 6 weeks does not change the concentration of thiocyanate in the sample by more than 10%

    Sulfur Metabolism of Three Autotrophic Iron-Oxidizers.

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    Spraying for prevention of apple blotch and apple scab

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    Cover title.Bibliography: p. 44-45.Mode of access: Internet

    Nautilia abyssi sp. nov., a thermophilic, chemolithoautotrophic, sulfur-reducing bacterium isolated from an East Pacific Rise hydrothermal vent

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    This is an author manuscript that has been accepted for publication in International Journal of Systematic and Evolutionary Microbiology, copyright Society for General Microbiology, but has not been copy-edited, formatted or proofed. Cite this article as appearing in International Journal of Systematic and Evolutionary Microbiology. This version of the manuscript may not be duplicated or reproduced, other than for personal use or within the rule of 'Fair Use of Copyrighted Materials' (section 17, Title 17, US Code), without permission from the copyright owner, Society for General Microbiology. The Society for General Microbiology disclaims any responsibility or liability for errors or omissions in this version of the manuscript or in any version derived from it by any other parties. The final copy-edited, published article, which is the version of record, can be found at http://mic.sgmjournals.org, and is freely available without a subscription.International audienceA novel strictly anaerobic, thermophilic, sulfur-reducing bacterium, designated PH1209(T), was isolated from an East Pacific Rise hydrothermal vent (1 degrees N) sample and studied using a polyphasic taxonomic approach. Cells were Gram-negative, motile rods (approx. 1.60 x 0.40 microm) with a single polar flagellum. Strain PH1209(T) grew at temperatures between 33 and 65 degrees C (optimum 60 degrees C), from pH 5.0 to 8.0 (optimum 6.0-6.5), and between 2 and 4 % (w/v) NaCl (optimum 3 %). Cells grew chemolithoautotrophically with H(2) as an energy source, S(0) as an electron acceptor and CO(2) as a carbon source. Strain PH1209(T) was also able to use peptone and yeast extract as carbon sources. The G+C content of the genomic DNA was 35 mol%. Phylogenetic analyses based on 16S rRNA gene sequencing showed that strain PH1209(T) fell within the order Nautiliales, in the class Epsilonproteobacteria. Comparative 16S rRNA gene sequence analysis indicated that strain PH1209(T) belonged to the genus Nautilia and shared 97.2 and 98.7 % 16S rRNA gene sequence identity, respectively, with the type strains of Nautilia lithotrophica and Nautilia profundicola. It is proposed, from the polyphasic evidence, that the strain represents a novel species, Nautilia abyssi sp. nov.; the type strain is PH1209(T) (=DSM 21157(T)=JCM 15390(T))

    Biomimetic sulfide oxidation by the means of immobilized Fe(III)-5,10,15,20-tetrakis(pentafluorophenyl)porphin under mild experimental conditions

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    This paper describes the oxidation of inorganic sulfide to sulfate, minimizing the formation of elemental sulfur. The described catalytic reaction uses dilute hydrogen peroxide at nearly neutral pH values in the presence of a bioinspired, heterogenized, and commercial ferriporphin. A substantial increase of the percentage of sulfide converted to sulfate is obtained in comparison with the yields obtained when working with hydrogen peroxide alone. The biomimetic catalyst also proved to be a much more efficient catalyst than horseradish peroxidase. Accordingly, it could be suitable for large-scale applications. Further studies are in progress to drive sulfate yields up to nearly quantitative
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