title: Co-amendment with halogenated compounds enhances anaerobic microbial dechlorination of 1,2,3,4-tetrachlorodibenzo-P-dioxin and 1,2,3,4-tetrachlorodibenzofuran in estuarine sediments.
abstract: Halogenated coamendments enhanced dechlorination of 31 microM of spiked 1,2,3,4-tetrachlorodibenzo-p-dioxin (TeCDD) and 49 microM of spiked 1,2,3,4-tetrachlorodibenzofuran (TeCDF) in sediments from San Diego Bay (CA, USA) and Tuckerton (NJ, USA). Dechlorination of 1,2,3,4-TeCDD occurred to a greater extent under methanogenic than under sulfate-reducing conditions. The most effective stimulation of 1,2,3,4-TeCDD dechlorination occurred with coamendment of 25 microM of 1,2,3,4-tetrachlorobenzene (TeCB), 2,3,4,5-tetrachloroanisole (TeCA), 2,3,4,5-tetrachlorophenol, or 2',3',4'-trichloroacetophenone plus 500 microM lactate and 500 microM propionate as electron donors. The 1,2,3,4-TeCDD dechlorination was evident after three months and sequentially produced mainly 1,2,4-trichlorodibenzo-p-dioxin, 1,3-dichlorodibenzo-p-dioxin, and 2-monochlorodibenzo-p-dioxin (MCDD). Monobromophenols (2-bromo-, 3-bromo-, and 4-bromophenol), monochlorophenols (2-chloro-, 3-chloro-, and 4-chlorophenol), 2,3,5,6-tetrachlorobenzoate, or electron donors alone stimulated less 1,2,3,4-TeCDD dechlorination, with activity apparent only after six months. The 1,2,3,4-TeCDD dechlorination produced 50 mol % 2-MCDD after six months in sediments from the more contaminated Graving Dock and Paleta Creek sites in San Diego Bay. The 1,2,3,4-TeCDD dechlorination by sediments from the less contaminated Shelter Island site in San Diego Bay and in pristine Tuckerton sediments did not produce 2-MCDD. Dechlorination of 1,2,3,4-TeCDF to tri- and dichlorinated daughter products was significantly enhanced by TeCB and TeCA. These results suggest that halogenated aromatic compounds with structural similarity to 1,2,3,4-TeCDD/F stimulate bacteria with the ability to dechlorinate chlorinated dibenzo-p-dioxin and furans.
authors.affiliation: Department of Biochemistry and Microbiology and Biotechnology Center for Agriculture and the Environment, Rutgers, The State University of New Jersey, New Brunswick, New Jersey 08901, USA.
authors.forename: Young-Beom
authors.initials: YB
authors.lastname: Ahn
authors.forename: Max M
authors.initials: MM
authors.lastname: Häggblom
authors.forename: Donna E
authors.initials: DE
authors.lastname: Fennell
mesh_terms: D000693:Anaerobiosis; D001421:Bacteria, Anaerobic / Q000187:drug effects* / Q000378:metabolism*; D001572:Benzofurans / Q000737:chemistry / Q000378:metabolism*; D002713:Chlorine / Q000378:metabolism*; D019015:Geologic Sediments / Q000737:chemistry*; D006219:Halogens / Q000737:chemistry / Q000494:pharmacology*; D008697:Methane / Q000378:metabolism; D015394:Molecular Structure; D000072317:Polychlorinated Dibenzodioxins / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D045483:Rivers / Q000382:microbiology; D013997:Time Factors; D014481:United States
chemical_list: D001572:Benzofurans; D006219:Halogens; D000072317:Polychlorinated Dibenzodioxins; D002713:Chlorine; C508215:1,2,3,4-tetrachlorodibenzofuran; C092155:1,2,3,4-tetrachlorodibenzodioxin; D008697:Methane