title: Growth inhibition by tungsten in the sulfur-oxidizing bacterium Acidithiobacillus thiooxidans.
abstract: Growth of five strains of sulfur-oxidizing bacteria Acidithiobacillus thiooxidans, including strain NB1-3, was inhibited completely by 50 microM of sodium tungstate (Na(2)WO(4)). When the cells of NB1-3 were incubated in 0.1 M beta-alanine-SO(4)(2-) buffer (pH 3.0) with 100 microM Na(2)WO(4) for 1 h, the amount of tungsten bound to the cells was 33 microg/mg protein. Approximately 10 times more tungsten was bound to the cells at pH 3.0 than at pH 7.0. The tungsten binding to NB1-3 cells was inhibited by oxyanions such as sodium molybdenum and ammonium vanadate. The activities of enzymes involved in elemental sulfur oxidation of NB1-3 cells such as sulfur oxidase, sulfur dioxygenase, and sulfite oxidase were strongly inhibited by Na(2)WO(4). These results indicate that tungsten binds to NB1-3 cells and inhibits the sulfur oxidation enzyme system of the cells, and as a result, inhibits cell growth. When portland cement bars supplemented with 0.075% metal nickel and with 0.075% metal nickel and 0.075% calcium tungstate were exposed to the atmosphere of a sewage treatment plant containing 28 ppm of H(2)S for 2 years, the weight loss of the portland cement bar with metal nickel and calcium tungstate was much lower than the cement bar containing 0.075% metal nickel.
authors.affiliation: Technical Research Institute, Hazama Corporation, Tsukuba, Japan.
authors.forename: Atsunori
authors.initials: A
authors.lastname: Negishi
authors.forename: Tadashi
authors.initials: T
authors.lastname: Muraoka
authors.forename: Terunobu
authors.initials: T
authors.lastname: Maeda
authors.forename: Fumiaki
authors.initials: F
authors.lastname: Takeuchi
authors.forename: Tadayoshi
authors.initials: T
authors.lastname: Kanao
authors.forename: Kazuo
authors.initials: K
authors.lastname: Kamimura
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Sugio
mesh_terms: D013856:Acidithiobacillus thiooxidans / Q000187:drug effects* / Q000201:enzymology / Q000254:growth & development*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004798:Enzymes / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D010084:Oxidation-Reduction; D012722:Sewage; D013455:Sulfur / Q000378:metabolism*; D014414:Tungsten / Q000494:pharmacology*; D017973:Tungsten Compounds / Q000494:pharmacology; D018505:Waste Management
chemical_list: D004791:Enzyme Inhibitors; D004798:Enzymes; D012722:Sewage; D017973:Tungsten Compounds; C025399:sodium tungstate(VI); D013455:Sulfur; D014414:Tungsten