experiments were set up to estimate the effectiveness of clinoptilolite for the removal ofarsenate from aqueous solutions. the removal of arsenate by the exchanged forms was analyzed in thelight of the langmuir model of adsorption. a kinetic study of adsorption was carried out at differentintervals of time, and the kad values were calculated by using lagergren’s equation. adsorption ofarsenate ...

The ability of anaerobic prokaryotes to employ different terminal electron acceptors for respiration enables these organisms to flourish in subsurface ecosystems. Desulfurispirillum indicum strain S5 is an obligate anaerobic bacterium that is able to grow by respiring a range of different electron acceptors, including arsenate and nitrate. Here, we examined the growth, electron acceptor utiliza...

Sagers, Richard D. (Brigham Young University, Provo, Utah), Moshe Benziman, and Sigrid M. Klein. Failure of arsenate to uncouple the phosphotransacetylase system in Clostridium acidiurici. J. Bacteriol. 86:978-984. 1963.-The conversion of pyruvate to acetyl phosphate by extracts of Clostridium acidiurici required coenzyme A (CoA), an electron-carrier system (ferredoxin and nicotinamide adenine ...

This research was undertaken to evaluate the effectiveness of a hybrid sorbent resin (Lewatit FO36) with goethite structure for removing arsenate from water. Column experiments (with constant flow rate of 8 mL/min, corresponding to 2 min empty bed contact time (EBCT)) were conducted to evaluate the adsorption capacity of resin before and after regeneration and effects of chloride, sulfate, bica...

Inorganic arsenic is a carcinogen, and its ingestion through foods such as rice presents a significant risk to human health. Plants chemically reduce arsenate to arsenite. Using genome-wide association (GWA) mapping of loci controlling natural variation in arsenic accumulation in Arabidopsis thaliana allowed us to identify the arsenate reductase required for this reduction, which we named High ...

The arsenic metabolism in different biological organisms has been studied extensively. However, little is known about protozoa. Herein, we investigated the cell stress responses of the freshwater ciliate Tetrahymena pyriformis to arsenate toxicity. An acute toxicity assay revealed an 18-h EC(50) arsenate concentration of ca. 40 μM, which caused significant changes in the cell shape, growth and ...

The mechanisms of arsenic (As) hyperaccumulation in Pteris vittata, the first identified As hyperaccumulator, are unknown. We investigated the interactions of arsenate and phosphate on the uptake and distribution of As and phosphorus (P), and As speciation in P. vittata. In an 18-d hydroponic experiment with varying concentrations of arsenate and phosphate, P. vittata accumulated As in the fron...

Brucella melitensis is the etiological agent responsible for brucellosis. Present in the B. melitensis genome is a 116-residue protein related to arsenate reductases (Bm-YffB; BR0369). Arsenate reductases (ArsC) convert arsenate ion (H(2)AsO(4)(-)), a compound that is toxic to bacteria, to arsenite ion (AsO(2)(-)), a product that may be efficiently exported out of the cell. Consequently, Bm-Yff...

In Shewanella sp. strain ANA-3, utilization of arsenate as a terminal electron acceptor is conferred by a two-gene operon, arrAB, which lacks a gene encoding a membrane-anchoring subunit for the soluble ArrAB protein complex. Analysis of the genome sequence of Shewanella putrefaciens strain CN-32 showed that it also contained the same arrAB operon with 100% nucleotide identity. Here, we report ...

Arsenic (As) accumulation in rice (Oryza sativa) may pose a significant health risk to consumers. Plants take up different As species using various pathways. Here, we investigated the contribution of the phosphate (Pi) transport pathway to As accumulation in rice grown hydroponically or under flooded soil conditions. In hydroponic experiments, a rice mutant defective in OsPHF1 (for phosphate tr...