Mutants of Salmonella typhimurium that lack the biosynthetic sulfite reductase (cysI and cysJ mutants) retain the ability to reduce sulfite for growth under anaerobic conditions (E. L. Barrett and G. W. Chang, J. Gen. Microbiol., 115:513-516, 1979). Here we report studies of sulfite reduction by a cysI mutant of S. typhimurium and purification of the associated anaerobic sulfite reductase. Sulf...

Ethane formation, as a measure of lipid peroxidation, was studied in spinach (Spinacia oleracea L.) chloroplasts exposed to sulfite. Ethane formation required sulfite and light, and occurred with concomitant oxidation of sulfite to sulfate. In the dark, both ethane formation and sulfite oxidation were inhibited. Ethane formation was stimulated by ferric or ferrous ions and inhibited by ethylene...

INTRODUCTION Hydrogen sulfide and related sulfur compounds produced internally by yeast during fermentation are considered highly undesirable if they are excreted and exceed threshold concentrations in the finished wine, as they cause an unpleasant "reduced character". The threshold for hydrogen sulfide is on the order of parts per billion and that for some of the other reduced sulfur compounds...

Exposure to (bi)sulfite (HSO3-) and sulfite (SO32-) has been shown to induce a wide range of adverse reactions in sensitive individuals. Studies have shown that peroxidase-catalyzed oxidation of (bi)sulfite leads to formation of several reactive free radicals, such as sulfur trioxide anion (.SO3-), peroxymonosulfate (-O3SOO.), and especially the sulfate (SO4. -) anion radicals. One such peroxid...

Thiobacillus thiooxidans cells oxidized elemental sulfur to sulfite, with 1 mol of O(2) consumption per mol of sulfur oxidized to sulfite, when the oxidation of sulfite was inhibited with 2-n-heptyl-4-hydroxyquinoline N-oxide.

A multiphase chemistry model coupled with a quasi-spectral microphysical model has been applied to measurements from the European CIME campaign to quantify the formation of the strong acids nitrate and sulfate, and to evaluate the role of microphysical processes in redistributing reactive species among the different phases (gas versus cloud and/or rain). Significant formation of nitrate and sul...

High concentrations of sulfur dioxide (SO(2) ) as an air pollutant, and its derivative sulfite, cause abiotic stress that can lead to cell death. It is currently unknown to what extent plant fumigation triggers specific transcriptional responses. To address this question, and to test the hypothesis that sulfite oxidase (SO) is acting in SO(2) detoxification, we compared Arabidopsis wildtype (W...

In phototrophic sulfur bacteria, sulfite is a well-established intermediate during reduced sulfur compound oxidation. Sulfite is generated in the cytoplasm by the reverse-acting dissimilatory sulfite reductase DsrAB. Many purple sulfur bacteria can even use externally available sulfite as a photosynthetic electron donor. Nevertheless, the exact mode of sulfite oxidation in these organisms is a ...

The biochemical basis for sulfite accumulation by sulfate-using revertants of Salmonella pullorum was determined. All of the sulfate-using mutants isolated from wild-type S. pullorum accumulated sulfite when grown at 37 but not at 25 C. The specific activity of reduced nicotinamide adenine dinucleotide (NADPH)-dependent sulfite reductase (H2S-NADP oxidoreductase, EC 1.8.1.2) and of reduced meth...

Most of the 36 billion gal of treated sewage wastewater discharged daily into the environment in the United States is disinfected via chlorination. To minimize toxicity, dechlorination with sulfite or sulfur dioxide is often performed. Although dechlorination is considered instantaneous and complete, several studies have found residual toxicity of chlorinated/dechlorinated effluent to aquatic l...