title: Deinococcus radiodurans engineered for complete toluene degradation facilitates Cr(VI) reduction.
abstract: Toluene and other fuel hydrocarbons are commonly found in association with radionuclides at numerous US Department of Energy sites, frequently occurring together with Cr(VI) and other heavy metals. In this study, the extremely radiation-resistant bacterium Deinococcus radiodurans, which naturally reduces Cr(VI) to the less mobile and less toxic Cr(III), was engineered for complete toluene degradation by cloned expression of tod and xyl genes of Pseudomonas putida. The recombinant Tod/Xyl strain showed incorporation of carbon from 14C-labelled toluene into cellular macromolecules and carbon dioxide, in the absence or presence of chronic ionizing radiation. The engineered bacteria were able to oxidize toluene under both minimal and complex nutrient conditions, and recombinant cells reduced Cr(VI) in sediment microcosms. As such, the Tod/Xyl strain could provide a model for examining the reduction of metals coupled to organic contaminant oxidation in aerobic radionuclide-contaminated sediments.
authors.affiliation: Department of Microbiology and Cancer Center, Howard University, 2041 Georgia Avenue N.W., Washington, DC 20060, USA.
authors.forename: Hassan
authors.initials: H
authors.lastname: Brim
authors.affiliation: Department of Chemistry, Manchester College, North Manchester, IN 46962, USA.
authors.forename: Jeffrey P
authors.initials: JP
authors.lastname: Osborne
authors.affiliation: Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352, USA.
authors.forename: Heather M
authors.initials: HM
authors.lastname: Kostandarithes
authors.affiliation: Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352, USA.
authors.forename: James K
authors.initials: JK
authors.lastname: Fredrickson
authors.affiliation: Department of Biochemistry, University of Minnesota, St Paul, MN 55108, USA.
authors.forename: Lawrence P
authors.initials: LP
authors.lastname: Wackett
authors.affiliation: Department of Pathology, Uniformed Services University of the Health Sciences(USUHS), Rm B3153, 4301 Jones Bridge Road, Bethesda, MD 20814, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Daly
mesh_terms: D002857:Chromium / Q000378:metabolism*; D034301:Deinococcus / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D019015:Geologic Sediments; D010084:Oxidation-Reduction; D011995:Recombination, Genetic; D014050:Toluene / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000378:metabolism
chemical_list: D014874:Water Pollutants, Chemical; D002857:Chromium; D014050:Toluene