Nerve agent-degrading enzymes Organophosphorus Acid Anhydrolase (OPAA) and Organophosphorus Hydrolase (OPH) covalently-coupled to solid supports were examined as drinking water system nerve agent decontaminants. Enzymes were bound to azlactone polyacrylamide, glyoxal agarose and glyoxal-aminopropyl controlled-pore glass and tested for stability in unbuffered tap water. Kinetic analyses showed t...

A set of random transposon vectors pUTTns that facilitates the markerless integration of new functions into the chromosome of gram-negative bacteria has been developed. The vectors, which are derived from mini-Tn5 transposons, are located on a R6K-based suicide delivery plasmid that provides the IS50(R) transposase tnp gene in cis, but they are external to the mobile element. The vectors' conju...

AIMS To develop a simple, rapid and sensitive fluorimetric assay to detect, isolate and characterize a soil bacterium capable of degrading the organophosphorus pesticide, coumaphos. METHODS AND RESULTS A high throughput microtitre plate-based method was used to quantify coumaphos hydrolysis by the bacterium. The fluorescent hydrolysis product of coumaphos, chlorferon, was detected at levels a...

objective: organophosphorus hydrolase (oph) is a homodimeric enzyme that can hydrolyze phosphoester bonds and reduce the toxicity of organophosphorus compounds. this makes oph a suitable element for the biodegradation of these compounds. methods: we successfully cloned the oph gene from pseudomonas diminuta, after optimization for pichia pastoris, into a yeast expression vector (ppiczαb). afte...

symptoms of the leaf scorch disease on the leaves of oleander infected by xylella fastidiosa appearing for the first time in lebanon were confirmed by elisa tests and anatomical observations of sections of petioles by a scanning electron microscope. xylella fastidiosa was detected in the xylem forming bacterial aggregates in the lumen of tracheary elements. the bacterium colonizes and invades t...

A quick, simple and effective chromatographic method for the separation of beryllium from a wide range of elements is described. The elements selected comprise elements which can interfere with the determination of beryllium by inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and elements which commonly occur in environmental and industrial sample matrices. Beryllium is separat...

background: long-term extraction and production of various oil derivatives causes contamination of soil adjacent to production and refining area. the main important issue is the ecological hazard of these pollutants. the main aim of the study was to identify and separate native bacteria that are responsible for degradation of oil contaminated fields. methods: we prepared a compound sample of co...

Organophosphorus poisoning is common in rural Asia. Clinical features result from overactivity of acetylcholine receptors. Blackish discoloration of urine is not a feature of organophosphorus poisoning. Only one case of black colored urine following quinalphos poisoning has been reported in literature. We report two cases of organophosphorus poisoning from two different compounds, following whi...