An investigation of the Hg2+ resistance mechanism of four freshwater and four coastal marine bacteria that did not hybridize with a mer operonic probe was conducted (T. Barkay, C. Liebert, and M. Gillman, Appl. Environ. Microbiol. 55:1196-1202, 1989). Hybridization with a merA probe, the gene encoding the mercuric reductase polypeptide, at a stringency of hybridization permitting hybrid formati...

The plasmid-determined mer operon, which provides resistance to inorganic mercury compounds, was subject to a 2.5-fold decrease in expression when glucose was administered at the same time as the inducer HgCl2. This glucose-mediated transient repression of the operon was overcome by the addition of cyclic AMP. Permanent catabolite repression of the operon was observed in the 1.6- to 1.9-fold de...

A cDNA encoding soybean (Glycine max [L.] Merr) ferric leghemoglobin reductase (FLbR), an enzyme that is postulated to play an important role in maintaining leghemoglobin in its functional ferrous state, has been cloned and characterized. A group of highly degenerate oligonucleotides deduced from the N-terminal amino acid sequence of FLbR was used to prime the polymerase chain reaction (PCR) on...

Background and Aims: Mercury, with its oxidative activity, causes damage to the antioxidant enzymes thus resulting in physiological disorders. Sodium selenide is an antioxidant that protects antioxidant enzymes. The aim of this study was to investigate the protective effect of sodium selenide on renal toxicity induced by mercuric chloride in rats. Materials and Methods: Animals were divided in...

background anaerobic-inducible promoters are alternatives of chemical-inducible promoters for expression of recombinant proteins especially in conditions where chemical induction is not possible or anaerobic conditions are preferable. the nirb promoter is the promoter of the first gene of nir operon in escherichia coli, which encodes nadh-dependent nitrite reductase. this promoter is naturally ...

After freezing and thawing, Pseudomonas aeruginosa harboring a drug resistance plasmid (Hg2+r, Strr), became acutely sensitive to mercuric ions but not to streptomycin in the plating medium, whereas its sensitivity to both agents became more pronounced indicating a synergistic effect. This freeze-thaw-induced sensitivity was transient and capable of being repaired to a simple salts medium. Tran...

A DNA gene probe was prepared to study genetic change mechanisms responsible for adaptation to mercury in natural bacterial communities. The probe was constructed from a 2.6-kilobase NcoI-EcoRI DNA restriction fragment which spans the majority of the mercury resistance operon (mer) in the R-factor R100. The range of specificity of this gene probe was defined by hybridization to the DNA of a wid...

Background: Exposure to any xenobiotic can disturb the metabolic activities of particular organs. Hence present study is designed to find changes in hepatic biochemistry, histochemistry and histopathology besides serum enzyme levels after acute and sub-acute treatment with mercuric chloride, a heavy metallic compound, in albino rat (Rattus norvegicus). Materials & methods: Thirty albino rat...