title: Dechlorination and organohalide-respiring bacteria dynamics in sediment samples of the Yangtze Three Gorges Reservoir.
abstract: Several groups of bacteria such as Dehalococcoides spp., Dehalobacter spp., Desulfomonile spp., Desulfuromonas spp., or Desulfitobacterium spp. are able to dehalogenate chlorinated pollutants such as chloroethenes, chlorobenzenes, or polychlorinated biphenyls under anaerobic conditions. In order to assess the dechlorination potential in Yangtze sediment samples, the presence and activity of the reductively dechlorinating bacteria were studied in anaerobic batch tests. Eighteen sediment samples were taken in the Three Gorges Reservoir catchment area of the Yangtze River, including the tributaries Jialing River, Daning River, and Xiangxi River. Polymerase chain reaction analysis indicated the presence of dechlorinating bacteria in most samples, with varying dechlorinating microbial community compositions at different sampling locations. Subsequently, anaerobic reductive dechlorination of tetrachloroethene (PCE) was tested after the addition of electron donors. Most cultures dechlorinated PCE completely to ethene via cis-dichloroethene (cis-DCE) or trans-dichloroethene. Dehalogenating activity corresponded to increasing numbers of Dehalobacter spp., Desulfomonile spp., Desulfitobacterium spp., or Dehalococcoides spp. If no bacteria of the genus Dehalococcoides spp. were present in the sediment, reductive dechlorination stopped at cis-DCE. Our results demonstrate the presence of viable dechlorinating bacteria in Yangtze samples, indicating their relevance for pollutant turnover.
authors: Department Environmental Biotechnology, DVGW-Technologiezentrum Wasser (TZW), Karlsruher Straße 84, 76139, Karlsruhe, Germany.
authors: Irene
authors: I
authors: Kranzioch
authors: Claudia
authors: C
authors: Stoll
authors: Andreas
authors: A
authors: Holbach
authors: Hao
authors: H
authors: Chen
authors: Lijing
authors: L
authors: Wang
authors: Binghui
authors: B
authors: Zheng
authors: Stefan
authors: S
authors: Norra
authors: Yonghong
authors: Y
authors: Bi
authors: Karl-Werner
authors: KW
authors: Schramm
authors: Andreas
authors: A
authors: Tiehm
mesh_terms: D001419:Bacteria / Q000145:classification / Q000302:isolation & purification / Q000378:metabolism*; D001673:Biodegradation, Environmental; D002681:China; D041862:Chloroflexi / Q000145:classification / Q000302:isolation & purification / Q000502:physiology; D045858:Desulfitobacterium / Q000145:classification / Q000302:isolation & purification / Q000502:physiology; D019015:Geologic Sediments / Q000737:chemistry / Q000382:microbiology*; D054879:Halogenation; D011078:Polychlorinated Biphenyls / Q000032:analysis / Q000378:metabolism; D013750:Tetrachloroethylene / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000378:metabolism*
chemical_list: D014874:Water Pollutants, Chemical; D011078:Polychlorinated Biphenyls; D013750:Tetrachloroethylene