A sulfur:ferric ion oxidoreductase that utilizes ferric ion (Fe3+) as an electron acceptor of elemental sulfur was purified from iron-grown Thiobacillus ferrooxidans to an electrophoretically homogeneous state. Under anaerobic conditions in the presence of Fe3+, the enzyme reduced 4 mol of Fe3+ with 1 mol of elemental sulfur to give 4 mol of Fe2+ and 1 mol of sulfite, indicating that it corresp...

The remediation of metal-contaminated sediment was studied using the bioleaching process with a mixed culture of sulfur-oxidizing bacteria. The effects of substrate concentration (elemental sulfur) on sediment acidification, sulfur oxidation and metal solubilization from contaminated sediment during the bioleaching process were investigated with free-cell suspensions. Sulfur concentration great...

Respiratory ammonification of nitrate is the microbial process that determines the retention of nitrogen in an ecosystem. To date, sulfur-dependent dissimilatory nitrate reduction to ammonium has been demonstrated only with sulfide as an electron donor. We detected a novel pathway that couples the sulfur and nitrogen cycles. Thermophilic anaerobic bacteria Thermosulfurimonas dismutans and Dissu...

Quantitative analysis by high-pressure liquid chromatography shows that all commercial samples of elemental sulfur besides S8 contain traces of S7 (up to 0.56%) and in some cases also S6, S9, and polymeric sulfur (S«,). Pure S8 can be obtained by recrystallization from CS2. Elemental sulfur minerals also quite often contain traces of S7 (up to 0.3%). Since neither irradiation by daylight at 20 ...

Sulfur-based autotrophic denitrification processes utilize autotrophic denitrifiers, such as Thiobacillus denitrificans and Thiomicrospira denitrificans, to reduce nitrate to nitrogen gas. Bench-scale experiments were conducted to evaluate the sulfur-based autotrophic denitrification process. This paper addresses three issues: (1) start-up and operation of a CSTR to provide an adequate seed sou...

Thiobacillus thiooxidans cells became more hydrophobic but less adhesive to elemental sulfur in the presence of increasing potassium phosphate concentrations. At a fixed concentration of potassium phosphate, however, there was a peak of both cell hydrophobicity and adhesion to sulfur at around pH 5. Oxidation of sulfur by the cells was affected in a complex manner by the phosphate concentration...

In previous reports we have described the toxicity of certain peptones and amino acids, particularly cystine, for brucellae (Schuhardt, Rode, Foster, and Oglesby, 1949; Schuhardt, Rode, and Oglesby, 1949). Subsequently, we found and reported that cystine per se is not toxic for these organims, and proved that the observed toxicity of autoclaved cystine is due to a heat-induced breakdown product...

The draft genome of Acidithiobacillus thiooxidans A01 contains 3,820,158 bp, with a G+C content of 53.08% and 3,660 predicted coding sequences (CDSs). The bacterium contains a series of specific genes involved in the oxidation of elemental sulfur and reduced inorganic sulfur compounds (RISCs).

The complete genome of Acidianus manzaensis YN-25 consists of a chromosome of 2,687,463 bp, with a G+C content of 30.62% and 2,746 coding DNA sequences. This archaeon contains a series of specific genes involved in the oxidation of elemental sulfur and reduced inorganic sulfur compounds.

A novel method combining elemental sulfur and selenium was developed, yielding crystalline sulfur-selenium compounds. The compounds were melted, and an organic comonomer added. Once the organic comonomer was consumed, the viscous compound was vitrified and allowed to cool yielding organic-inorganic hybrid polymers that are termed Organically Modified Chalcogenide (ORMOCHALC) polymers.