Growth Inhibition by Tungsten in the Sulfur-Oxidizing BacteriumAcidithiobacillus 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.

Improving wastewater management using free nitrous acid (FNA)

“…To inhibit the growth and the activity of SOM on the concrete surface, various surface treatment methods are widely applied. This includes the blending of biocides or inhibitors into the concrete (Negishi et al 2005); elevating surface pH of concrete by application of magnesium hydroxide (Davis et al 1998) and antimicrobial coatings such as silver-loaded zeolite and polymers (Haile andNakhla 2010, Lebrero et al 2011). Among all the approaches, the environmental footprint due to chemicals application, the cost and the difficulty of surface coating cause further concerns regarding expenditure and safety.…”

A novel and simple treatment for control of sulfide induced sewer concrete corrosion using free nitrous acid

“…The mechanisms of these methods include: reducing the biological sulfide oxidizing activity through removing the corrosion layer by high pressure washing (Islander et al, 1991;Nielsen et al, 2008); increasing the surface pH and deactivating the sulfide oxidizing bacteria by application of magnesium hydroxide (Rhee and Verdes, 2012;Sydney et al, 1996); inhibiting or deactivating the SOB through adding biocides or inhibitors into the concrete (Negishi et al, 2005;Yamanaka et al, 2002); or implementing a corrosion resistant surface by application of antimicrobial coatings, e.g. silver bearing zeolite, epoxy and polymer fibre (Berndt, 2011;De Muynck et al, 2009;.…”

Aerobic Degradation of Mercaptosuccinate by the Gram-Negative BacteriumVariovorax paradoxusStrain B4

“…The inhibitory effect of acrylic acid, a potent inhibitor of the ␤-oxidation of fatty acids (77), and of tungstate, an inhibitor competitive with molybdate in molybdoenzymes leading to inactive enzyme proteins (57), on the growth of V. paradoxus strain B4 was investigated. Cells were cultivated in MSM containing 0.5% (wt/vol) MS or 0.5% (wt/vol) sodium gluconate as a sole carbon source, and subsequently acrylic acid or sodium tungstate was added to a concentration of 2.5 or 10 mM, respectively.…”