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Genes encoding mercuric reductases from selected gram-negative aquatic bacteria have a low degree of homology with merA of transposon Tn501

Journal Article · · Applied and Environmental Microbiology; (USA)
OSTI ID:6651551
; ;  [1]
  1. Environmental Protection Agency, Gulf Breeze, FL (USA)
An investigation of the Hg{sup 2+} resistance mechanism of four freshwater and four coastal marine bacteria that did not hybridize with a mer operonic probe was conducted. Hybridization with a merA probe, the gene encoding the mercuric reductase polypeptide, at a stringency of hybridization permitting hybrid formation between evolutionarily distant merA genes (as exists between gram-positive and -negative bacteria), merA sequences in the genomes of all tested strains. Inducible Hg{sup 2+} volatilization was demonstrated for all eight organisms, and NADPH-dependent mercuric reductase activities were detected in crude cell extracts of six of the strains. Because these strains represented random selections of bacteria from three aquatic environments, it is concluded that merA encodes a common molecular mechanism for Hg{sup 2+} resistance and volatilization in aerobic heterotrophic aquatic communities.
OSTI ID:
6651551
Journal Information:
Applied and Environmental Microbiology; (USA), Journal Name: Applied and Environmental Microbiology; (USA) Vol. 56:6; ISSN 0099-2240; ISSN AEMID
Country of Publication:
United States
Language:
English