A wide range of microorganisms was tested to determine their sensitivity to low concentrations of bisulfite-sulfite and nitrite, solubility products of SO2 and NO2, respectively. Photosynthesis by blue-green algae (cyanobacteria) was more strongly inhibited by 0.1 mM bisulfite-sulfite and 1 mM nitrite at pH 6.0 than photosynthesis by eucaryotic algae and respiration of bacteria, fungi, and prot...

A simple 4-hydroxynaphthalimide-derived colorimetric and ratiometric fluorescent probe (1) containing a receptor of levulinate moiety was designed and synthesized to monitor sulfite. Probe 1 could quantificationally detect sulfite by a ratiometric fluorescence spectroscopy method with high selectivity and sensitivity. Specially, probe 1 exhibited a 100 nm red-shifted absorption spectrum along w...

The utilization of organosulfonates as carbon sources by aerobic or nitrate-reducing bacteria usually involves a measurable, uncharacterized sulfite dehydrogenase. This is tacitly assumed to be sulfite : ferricytochrome-c oxidoreductase [EC 1.8.2.1], despite negligible interaction with (eukaryotic) cytochrome c: the enzyme is assayed at high specific activity with ferricyanide as electron accep...

One is used to considering sulfite oxidation as part of a lithotrophic process (e.g. SorAB or Sox system), much of which involves neutral or ionic inorganic sulfur species on the outer surface of the cytoplasmic membrane. In contrast, the processes referred to in this chapter involve organic compounds, which (1) include a highly stable sulfonate substituent (C−SO 3 ), (2) are involved in the or...

Plant NiR (nitrite reductase) and SiR (sulfite reductase) have common structural and functional features. Both enzymes are generally distinguished in terms of substrate specificity for nitrite and sulfite. The genome of Cyanidioschyzon merolae, a unicellular red alga living in acidic hot springs, encodes two SiR homologues, namely CmSiRA and CmSiRB (C. merolae sulfite reductases A and B), but n...

The mechanism of prostaglandin synthase-dependent (bi)sulfite (hydrated sulfur dioxide) oxidation was investigated using an enzyme preparation derived from ram seminal vesicles. The horseradish peroxidase-catalyzed oxidation of (bi)sulfite was used as a model system. Incubation of (bi)sulfite with prostaglandin synthase and arachidonic acid, 15-hydroperoxyarachidonic acid, or H2O2 results in th...

An ssu2 mutation in Saccharomyces cerevisiae, previously shown to cause sulfite sensitivity, was found to be allelic to GRR1, a gene previously implicated in glucose repression. The suppressor rgt1, which suppresses the growth defects of grr1 strains on glucose, did not fully suppress the sensitivity on glucose or nonglucose carbon sources, indicating that it is not strictly linked to a defect ...

Sulfite oxidase catalyzes the terminal reaction in the degradation of sulfur amino acids. Genetic deficiency of sulfite oxidase results in neurological abnormalities and often leads to death at an early age. The mutation in the sulfite oxidase gene responsible for sulfite oxidase deficiency in a 5-year-old girl was identified by sequence analysis of cDNA obtained from fibroblast mRNA to be a gu...

Theoretical ab initio quantum mechanical charge field molecular dynamics (QMCF MD) has been applied in conjunction with experimental large angle X-ray scattering (LAXS) and EXAFS measurements to study structure and dynamics of the hydrated oxo chloro anions chlorite, ClO2(-), chlorate, ClO3(-), and perchlorate, ClO4(-). In addition, the structures of the hydrated hypochlorite, ClO(-), bromate, ...

BACKGROUND Sulfur dioxide, formed during the combustion of fossil fuels, is a major air pollutant near large cities. Its two ionized forms in aqueous solution, sulfite and (bi)sulfite, are widely used as preservatives and antioxidants to prevent food and beverage spoilage. (Bi)sulfite can be oxidized by peroxidases to form the very reactive sulfur trioxide anion radical (*SO(3)-). This free rad...