Mercury organomercurial resistance

Clark, D. L., A. A. Weiss, and S. Silver. 1977. Mercury and organomercurial resistance determined by plasmids in Pseudomonas. J. Bacteriol. 132 186-196. 

Amongthe Enterobacteriaceae, plasmids may carry genes specifying resistance to antibiotics and in some instances to mercury, organomercury and other cations and some anions. Mercury resistance is inducible and is not the result of training or tolerance. Transposon (Tn)501, conferring mercury resistance, has been widely studied. Plasmids conferring resistance to mercury are of two types ... 

Misra, T.K., Bacterial resistances to inorganic mercury salts and organomercurials, Plasmid, 27 (1), 4-16, 1992. 

Robinson, J.B. and O.H. Touvinen. 1984. Mechanisms of microbial resistance and detoxification of mercury and organomercury compounds physiological, biochemical and genetic analysis. Microbiol. Rev. 48 95-124. 

A method for detecting methylmercury in biological samples by its enzymatic conversion to methane is an alternative biological technique for methylmercury or other organomercurial analyses (Baldi and Filippelli 1991). Pseudomonasputida strain FBI, a broad spectrum mercury-resistant strain, is able to enzymatically convert methylmercury to Hg° and methane either in whole cell or in cell-free extracts. GC/FID was used to determine methane produced by the biological derivatization of methylmercury. The detection limit was 15 ng of methylmercury extracted from 1 g of biological tissue. The coefficient of variation was 1.9%. Chemical interferences are negligible in the enzymatic determination of methyl-... 

Enzymatic detoxification was determined to be the major resistance mechanism in all species of mercury-resistant bacteria. For example, mercuric reductase was essential for volatilization of Hg from Hg + and various organomercurial hydrolases were responsible for volatilization of methane (CH4) from methylmercury, for ethane (C2H4) from ethylmercury, and for benzene from phenylmercury. Minamata Bay bacterial isolates can also volatilize Hg from added inorganic and organic mercurials. Genes which govern the chemistry of mercury detoxification were abundant in bacteria found in Minamata Bay and other mercury-polluted sites these genetic strains of mercury-resistant bacteria show promise for bioremediation of mercury pollution. 

Organomercurials give the reactions shown in Fig. 14.1. Halogenation is useful not only to prepare organic halides but also to determine the position of attachment of the mercury atom in the original compound. Mercury-bound R groups are easily transferred to Pd, and if they resist p elimination, can be used in a variety of transformations shown in Fig. 4.1. 

Walts AE, Walsh CT (1988) Bacterial organomercurial lyase novel enzymatic protonolysis of organostannanes. J Am Chem Soc 110 1950-1953 Wang Y, Moore M, Levinson HS, Silver S, Walsh C, Mahler I (1989) Nucleotide sequence of a chromosomal mercury resistance determinant from a Bacillus sp. with broad-spectrum mercury-resistance. J Bacteriol 171 83-92 Williams JR, Morgan A, Rouch DA, Brown NL, Lee BTO (1993) Copper-resistant enteric bacteria from United Kingdom and Australian piggeries. Appl Environ Microbiol 59 2531-2537... 

Organomercury compounds such as phenylmercury acetate, methylmer-cury chloride, methoxjmiercury chloride, react with diphenylcarbazone in the same way as do inorganic mercury compounds, but they are resistant to reduction with zinc dust and are soluble in benzene. They may be detected by paper chromatography on filter paper. ... 

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