Hepatorenal dysfunctions in lead pollution.

Environmental and occupational lead pollution is a common problem in both developing and industrialised countries. Both hepatotoxicity and nephrotoxicity are known to occur in persons with exposure to heavy metals. We studied both liver function and renal function and blood lead concentraton in random population sample of 372 men (age range, 24 to 55 years). In all the subjects we measured both liver and renal function tests and both blood lead and urinary concentration of lead. Raised blood and urinary lead concentrations were associated with moderate changes in liver function and abnormal renal function, reflected in decrease of albumin and increased levels of liver enzymes and raised urea and creatinine concentrations, and with a reduction in creatinine clearance rate as compared to apparently normal subjects. These findings emphasis the importance of measurement of blood lead concentrations in adults in the genereal population to combat the effects of lead toxicity before the clinical signs predominate.

Mercury detoxifying enzymes within endospores of a broad-spectrum mercury resistant Bacillus pasteurii strain DR2.

Bacillus pasteurii DR2, a broad-spectrum Hg-resistant bacterial strain, exhibited delayed sporulation and less mercury volatilization in the presence of mercury compounds. However, Hg-sensitive Bacillus subtilis sporulated quickly in the presence of HgCl2 and volatilized no mercury. Levels of Hg2+-reductase and organomercurial lyase in the endospores of Bacillus pasteurii DR2 were lower than those in vegetative cells.

A PMA degrading constitutive organomercurial lyase in a broad-spectrum mercury resistant Bacillus pasteurii strain DR2.

A broad-spectrum Hg-resistant strain of B. pasteurii DR2 utilized phenylmercuric acetate (PMA) as sole source of carbon. This bacterial strain contained a constitutive organomercurial lyase which specifically degraded PMA but not other organo-mercurials. This PMA-lyase activity was also stimulated to different extents when this bacterial strain was grown in presence of different organic compounds as sole source of carbon.

Detoxification of mercury and organomercurials by nitrogen-fixing soil bacteria.

Minimal inhibitory concentration values of HgCl2 and 5 organomercurials were determined against 24 mercury-resistant N2-fixing soil bacteria previously isolated from soil and identified in our laboratory. These bacterial strains also displayed multiple antibiotic resistant properties. Typical growth pattern of a highly mercury-resistant Beijerinckia sp (KDr2) was studied in liquid broth supplemented with toxic levels of mercury compounds. Four bacterial strains were selected for determining their ability to volatilize mercury and their Hg-volatilizing capacity was different. Cell-free extracts prepared from overnight mercury-induced cells catalyzed Hg2+-induced NADPH oxidation. Specific activities of Hg2+-reductase which is capable of catalyzing conversion of Hg2+ →Ηg (o) of 10 Hg-resistant bacterial strains are also reported.