title: Metal resistance among aerobic chemoheterotrophic bacteria from the deep terrestrial subsurface.
abstract: The metal resistance of 350 subsurface bacterial strains from two U.S. Department of Energy facilities, the Savannah River Site (SRS), South Carolina, and the Hanford site, Washington, was determined to assess the effect of metal toxicity on microorganisms in the deep terrestrial subsurface. Resistance was measured by growth inhibition around discs containing optimized amounts of Hg(II), Pb(II), and Cr(VI). A broad range of resistance levels was observed, with some strains of Arthrobacter spp. demonstrating exceptional tolerance. A higher level of resistance to Hg(II) and Pb(II) (P < 0.05) and a higher occurrence of multiple resistances suggested that metals more effectively influenced microbial evolution in subsurface sediments of the SRS than in those of the Hanford site. Common resistance to heavy metals suggests that toxic metals are unlikely to inhibit bioremediation in deep subsurface environments that are contaminated with mixed wastes.
authors.affiliation: Department of Biochemistry and Microbiology, Cook College, Rutgers University, 76 Lipman Dr., New Brunswick, NJ 08901, USA.
authors.forename: G
authors.initials: G
authors.lastname: Benyehuda
authors.forename: J
authors.initials: J
authors.lastname: Coombs
authors.forename: P L
authors.initials: PL
authors.lastname: Ward
authors.forename: D
authors.initials: D
authors.lastname: Balkwill
authors.forename: T
authors.initials: T
authors.lastname: Barkay
mesh_terms: D001420:Bacteria, Aerobic / Q000145:classification / Q000187:drug effects* / Q000254:growth & development; D001673:Biodegradation, Environmental; D002857:Chromium / Q000633:toxicity; D005618:Fresh Water; D019015:Geologic Sediments / Q000382:microbiology*; D007854:Lead / Q000633:toxicity; D008670:Metals / Q000378:metabolism / Q000633:toxicity*; D008826:Microbial Sensitivity Tests; D012834:Silver / Q000633:toxicity
chemical_list: D008670:Metals; D002857:Chromium; D007854:Lead; D012834:Silver