title: Uranium removal and microbial community in a H2-based membrane biofilm reactor.
abstract: We evaluated a hydrogen-based membrane biofilm reactor (MBfR) for its capacity to reduce and remove hexavalent uranium [U(VI)] from water. After a startup period that allowed slow-growing U(VI) reducers to form biofilms, the MBfR successfully achieved and maintained 94-95% U(VI) removal over 8 months when the U surface loading was 6-11 e(-) mEq/m(2)-day. The MBfR biofilm was capable of self-recovery after a disturbance due to oxygen exposure. Nanocrystalline UO2 aggregates and amorphous U precipitates were associated with vegetative cells and apparently mature spores that accumulated in the biofilm matrix. Despite inoculation with a concentrated suspension of Desulfovibrio vulgaris, this bacterium was not present in the U(VI)-reducing biofilm. Instead, the most abundant group in the biofilm community contained U(VI) reducers in the Rhodocyclaceae family when U(VI) was the only electron acceptor. When sulfate was present, the community dramatically shifted to the Clostridiaceae family, which included spores that were potentially involved in U(VI) reduction.
authors: Swette Center for Environmental Biotechnology, Biodesign Institute, Arizona State University, USA.
authors: Chen
authors: C
authors: Zhou
authors: Swette Center for Environmental Biotechnology, Biodesign Institute, Arizona State University, USA. Electronic address: avontive@asu.edu.
authors: Aura
authors: A
authors: Ontiveros-Valencia
authors: Swette Center for Environmental Biotechnology, Biodesign Institute, Arizona State University, USA; Institut Sup'Biotech de Paris, France.
authors: Louis
authors: L
authors: Cornette de Saint Cyr
authors: Swette Center for Environmental Biotechnology, Biodesign Institute, Arizona State University, USA.
authors: Alexander S
authors: AS
authors: Zevin
authors: Swette Center for Environmental Biotechnology, Biodesign Institute, Arizona State University, USA.
authors: Sara E
authors: SE
authors: Carey
authors: Swette Center for Environmental Biotechnology, Biodesign Institute, Arizona State University, USA.
authors: Rosa
authors: R
authors: Krajmalnik-Brown
authors: Swette Center for Environmental Biotechnology, Biodesign Institute, Arizona State University, USA.
authors: Bruce E
authors: BE
authors: Rittmann
mesh_terms: D001419:Bacteria / Q000254:growth & development / Q000302:isolation & purification* / Q000378:metabolism; D018441:Biofilms; D003013:Clostridium / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism; D016969:Desulfovibrio vulgaris / Q000254:growth & development; D006859:Hydrogen / Q000737:chemistry; D008567:Membranes, Artificial; D012336:RNA, Ribosomal, 16S / Q000032:analysis; D043362:Rhodocyclaceae / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism; D013431:Sulfates / Q000378:metabolism; D014501:Uranium / Q000302:isolation & purification* / Q000378:metabolism; D014875:Water Pollutants, Radioactive / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*
chemical_list: D008567:Membranes, Artificial; D012336:RNA, Ribosomal, 16S; D013431:Sulfates; D014875:Water Pollutants, Radioactive; D014501:Uranium; D006859:Hydrogen
keywords: Bicarbonate; MBfR; Spore; Sulfate; U removal; Uraninite