Cadmium- and mercury-resistant Bacillus strains from a salt marsh and from Boston Harbor

I Mahler, H S Levinson, Y Wang, H O Halvorson
1986 Applied and Environmental Microbiology  
Bacteria resistant to cadmium or mercury or both were isolated from the Great Sippewissett Marsh (Cape Cod, Mass.) and from Boston Harbor. Many of these metal-resistant isolates were gram-positive aerobic sporeformers, although not necessarily isolated as spores. Although several of the isolated strains bore plasmids, cadmium and mercury resistances appeared to be, for the most part, chromosomally encoded. DNA sequence homology of the gram-positive cadmiumand mercury-resistant isolates was not
more » ... t isolates was not demonstrable with metal resistance genes from plasmids of either gram-positive (p1258) or gram-negative (pDB7) origin. Cadmium resistance of all the marsh isolates tested resulted from reduced Cd2+ transport. On the other hand, three cadmium-resistant harbor isolates displayed considerable influx but no efflux of Cd2+. Hg-resistant strains detoxified mercury by transforming Hg2+ to volatile Hgo via mercuric reductase. Lomb Spectronic 20 spectrophotometer). 1293 on May 7, 2020 by guest http://aem.asm.org/ Downloaded from 1294 MAHLER ET AL.
doi:10.1128/aem.52.6.1293-1298.1986 fatcat:gm2aljs2kzb55fgqag5h4qmvza