The arsenate poisoning of R17 phage eclipse in Escherichia coli cultures grown in glycerol-containing medium has been found to be mediated by a dramatic loss in cell-associated F pili. Poisoning was very rapid and was nearly complete within 3 min at 37 C. The loss of pili was reflected by a 90% reduction in the ability of these cells to attach ribonucleic acid phage and by a reduction in the pi...

Steady exposure to environmental arsenic has led to the evolution of vital cellular detoxification mechanisms. Under aerobic conditions, a two-step process appears most common among microorganisms involving reduction of predominant, oxidized arsenate (H(2)As(V)O(4)(-)/HAs(V)O(4)(2-)) to arsenite (As(III)(OH)(3)) by a cytosolic enzyme (ArsC; Escherichia coli type arsenate reductase) and subseque...

Arsenic (As) is toxic, carcinogenic and causes serious health problems. While As occurs naturally due to volcanic activity, the major anthropogenic sources of As are metal processing, burning of coal and arsenic-based pesticides or herbicides. Arsenate (AsO4) and arsenite (AsO3) are the primary chemical forms found in soil. Because of the wide distribution of arsenic compounds, arsenic resistan...

Chemical control of insects is considered one of the most beneficial developments of civilization (Klassen & Schwartz, 1983). As long ago as 1000 B.C., sulfur compounds were used to control insects in Asia Minor (National Academy of Science, 1969). However, the extensive use of chemicals to control pests has developed only in the last 150 years. The first example of large-scale effective chemic...

Arsenic is a long-known poison of environmental and industrial origin. Prolonged exposure is associated with vascular disease, skin lesions and cancer. The predominant form of arsenic in the nature is the pentavalent arsenate (AsV), which enters the body mainly via contaminated drinking water. Administration of sub lethal dose i.e 4.2 mg/kg/body weight was given to albino mice as single, double...

red mud (rm), a waste tailing from alumina production, (as an important environmental problem), can be used as a strong absorbent pollutant. in this study, the modified red mud (mrm) and pillared clay (pilc) were used for the removal of arsenate from water. the modified red mud (mrm) and pilc complex were characterized using xrd, sem and xrf microanalysis. the adsorption of arsenate on modified...

The uptake of arsenate (As(V)) and dimethylarsinic acid (DMAA) by aquatic macrophyte Spirodela polyrhiza L. was investigated to determine the influence of arsenic interaction with PO4(3-) and Fe ions. Plants were grown hydroponically on standard Murashige and Skoog (MS) culture solutions. Arsenic concentrations in Fe-oxide (Fe-plaque) on plant surfaces were determined by citrate-bicarbonate-eth...