In many parts of the world, groundwater contains so much arsenic that it builds up in irrigated crops. Linked to cancer and heart disease, this toxic element is particularly worrisome in rice, which absorbs arsenic more readily than other grains and is a staple for billions of people. Countries with the double whammy of arsenic-laced groundwater and heavy rice consumption include Bangladesh, In...

We here report the draft assembly for the genome of Pantoea sp. strain IMH, isolated from arsenic-contaminated soil in Inner Mongolia, China, with the ability to aerobically reduce arsenate to arsenite. The genome sequence will allow for the characterization of the molecular mechanisms of arsenate reduction.

A strictly anaerobic arsenate-respiring bacterium isolated from a gold mine in Bendigo, Victoria, Australia, belonging to the genus Bacillus is described. Cells are Gram-positive, motile rods capable of respiring with arsenate and nitrate as terminal electron acceptors using a variety of substrates, including acetate as the electron donor. Reduction of arsenate to arsenite is catalysed by a mem...

Kinetic data indicate that rabbit muscle glyceraldehyde d-phosphate dehydrogenase possesses two types of diphosphopyridine nucleotide-binding sites. The actual chemical reaction (oxidation-reduction) occurs at tight sites. Binding of DPN to loose sites activates the reaction at the tight sites. These results are consistent with the concept that the enzyme is “double headed,” with oxidation-redu...

Arsenate resistance is exhibited by the ericoid mycorrhizal fungus Hymenoscyphus ericae collected from As-contaminated mine soils. To investigate the mechanism of arsenate resistance, uptake kinetics for arsenate (H(2)AsO(4)(-)), arsenite (H(3)AsO(3)), and phosphate (H(2)PO(4)(-)) were determined in both arsenate-resistant and -non-resistant H. ericae. The uptake kinetics of H(2)AsO(4)(-), H(3)...

The fresh water unicellular green alga Chlamydomonas reinhardtii was used to explore whether it could function as a model system to identify proteins that are differentially expressed in response to arsenate exposure. Cells were treated with different concentrations of arsenate ranging from 100 400 M. When exposed to 200 M arsenate, the amount of live cells started to lessen on the second day...

Phosphorus affects the sorption of many metals and arsenate to iron (hydr)oxides. This may influence the mobility and bioavailability of metals and arsenate in soil and water. Phosphorus therefore plays an important role in, e.g., determining the ecotoxicological risk of contaminants in soils. The overall aim of this thesis was to improve the understanding of lead(II), copper(II), cadmium(II) a...

Leaching of arsenic (As) from chromated copper arsenate (CCA)-treated wood may elevate soil arsenic levels. Thus, an environmental concern arises regarding accumulation of As in vegetables grown in these soils. In this study, a greenhouse experiment was conducted to evaluate As accumulation by vegetables from the soils adjacent to the CCA-treated utility poles and fences and examine the effects...

Here, we report a draft genome sequence of Geobacter sp. strain OR-1, an arsenate-respiring bacterium isolated from Japanese paddy soil. It contained two distinct arsenic islands, one including genes for a respiratory arsenate reductase (Arr) as well as for arsenic resistance (arsD-arsA-acr3-arsR-arrA-arrB) and the second containing only genes for arsenic resistance.

Wolfe-Simon et al. (Research Articles, 3 June 2011, p. 1163; published online 2 December 2010) argued that the bacterial strain GFAJ-1 can vary the elemental composition of its biomolecules by substituting arsenic for phosphorus. Although their data show that GFAJ-1 is an extraordinary extremophile, consideration of arsenate redox chemistry undermines the suggestion that arsenate can replace th...