title: Electrochemical stimulation of microbial cis-dichloroethene (cis-DCE) oxidation by an ethene-assimilating culture.
abstract: This study investigated the feasibility of using a polarized graphite electrode as direct or indirect (via electrolytic oxygen generation) electron acceptor to stimulate the microbial oxidation of cis-dichloroethene (cis-DCE) in contaminated groundwater. A microbial culture was enriched in the anode chamber of a bioelectrochemical cell using a mixture of cis-DCE and ethene as substrates. The bioelectrochemical cell was operated by controlling the anode potential at +1.0 V or +1.5 V versus the standard hydrogen electrode (SHE). Enhanced cometabolic removal of cis-DCE, with ethene serving as the growth substrate, was observed in batch tests with the anode polarized at +1.5 V versus SHE. At this potential, (chloro)ethenes removal was probably sustained by molecular oxygen generated at the anode from water oxidation. Conversely, negligible anaerobic degradation was observed at +1.0 V versus SHE (a potential which does not allow oxygen generation), hence suggesting that molecular oxygen is needed to initiate (chloro)ethene degradation. PCR-DGGE analysis of the microbial culture followed by band sequencing and phylogenetic analysis evidenced the selective enrichment of a Bacillus species, providing a strong indication that this microorganism was responsible for cis-DCE and ethene degradation.
authors.affiliation: Water Research Institute, National Research Council (IRSA-CNR), Via Salaria km 29.300, 00015 Monterotondo, RM, Italy. Electronic address: aulenta@irsa.cnr.it.
authors.forename: Federico
authors.initials: F
authors.lastname: Aulenta
authors.forename: Roberta
authors.initials: R
authors.lastname: Verdini
authors.forename: Marco
authors.initials: M
authors.lastname: Zeppilli
authors.forename: Giulio
authors.initials: G
authors.lastname: Zanaroli
authors.forename: Fabio
authors.initials: F
authors.lastname: Fava
authors.forename: Simona
authors.initials: S
authors.lastname: Rossetti
authors.forename: Mauro
authors.initials: M
authors.lastname: Majone
mesh_terms: D001407:Bacillus / Q000254:growth & development / Q000378:metabolism*; D001673:Biodegradation, Environmental; D004000:Dichloroethylenes / Q000737:chemistry / Q000378:metabolism*; D004566:Electrodes; D005030:Ethylenes / Q000737:chemistry / Q000378:metabolism*; D006108:Graphite; D010084:Oxidation-Reduction
chemical_list: D004000:Dichloroethylenes; D005030:Ethylenes; D006108:Graphite; C036216:ethylene