title: Biodegradation of coplanar polychlorinated biphenyls by anaerobic microorganisms from estuarine sediments.
abstract: In this study, we investigated the biodegradability of biphenyl and 5 congeners (one non-planar and four coplanar) of polychlorinated biphenyl (PCB). Biphenyl, the non-planar congener 2,3',4',5-tetrachlorobiphenyl (25-34 CB), and the four coplanar congeners 3,3',4,4'-tetrachlorobiphenyl (34-34 CB), 3,4,4',5-tetrachlorobiphenyl (345-4 CB), 3,3',4,4',5-pentachlorobiphenyl (345-34 CB), and 3,3',4,4',5,5'-hexachlorobiphenyl (345-345 CB) were amended at a concentration of 10 mg/L into anoxic sediment slurries collected from the estuaries of the Tansui River and the Erjen River. During 2 years' incubation under sulfidogenic conditions, biphenyl was persistent, while all other chlorinated congeners, except for 345-345 CB, were dechlorinated with or without a lag period in sediment slurries collected from both rivers. Dechlorination of coplanar and non-planar congeners began with para chlorine removal. All para chlorines from the mono-, di-, and trichlorobiphenyl groups could be removed by sediment slurries from both rivers. Microbial communities in sediment from the Erjen River additionally fostered meta-dechlorination activity, but only after removal of all the para chlorines. Addition of Tween 20 (0.05%, v/v) into sediment slurries from the Tansui River did not enhance dechlorination rates or extents, but the addition of toluene- or 3-chlorobenzoate-adapted sediments enhanced dechlorination of 34-34 CB and 345-4 CB.
authors.affiliation: Institute of Marine Biology, National Taiwan Ocean University, Keelung, Taiwan, Republic of China.
authors.forename: C E
authors.initials: CE
authors.lastname: Kuo
authors.forename: S M
authors.initials: SM
authors.lastname: Liu
authors.forename: C
authors.initials: C
authors.lastname: Liu
mesh_terms: D000693:Anaerobiosis; D001673:Biodegradation, Environmental; D004785:Environmental Pollutants / Q000493:pharmacokinetics*; D019015:Geologic Sediments / Q000737:chemistry / Q000382:microbiology; D011078:Polychlorinated Biphenyls / Q000493:pharmacokinetics*; D012988:Soil Microbiology
chemical_list: D004785:Environmental Pollutants; D011078:Polychlorinated Biphenyls