title: Interaction of perchlorate and trichloroethene bioreductions in mixed anaerobic culture.
abstract: This work evaluated the interaction of perchlorate and trichloroethene (TCE), two common co-contaminants in groundwater, during bioreduction in serum bottles containing synthetic mineral salts media and microbial consortia. TCE at concentrations up to 0.3mM did not significantly affect perchlorate reduction; however, perchlorate concentrations higher than 0.1mM made the reduction of TCE significantly slower. Perchlorate primarily inhibited the reduction of vinyl chloride (VC, a daughter product of TCE) to ethene. Mechanistic analysis showed that the inhibition was mainly because perchlorate reduction is thermodynamically more favorable than reduction of TCE and its daughter products and not because of toxicity due to accumulation of dissolved oxygen produced during perchlorate reduction. As the initial perchlorate concentration increased from 0 to 600mg/L in a set of serum bottles, the relative abundance of Rhodocyclaceae (a putatively perchlorate-reducing genus) increased from 6.3 to 80.6%, while the relative abundance of Dehalococcoides, the only known genus that is able to reduce TCE all the way to ethene, significantly decreased. Similarly, the relative abundance of Proteobacteria (a phylum to which most known perchlorate-reducing bacteria belong) increased from 22% to almost 80%.
authors.affiliation: Department of Environmental Engineering, College of Environmental and Resource Science, Zhejiang University, Hangzhou, China; Zhejiang Prov Key Lab Water Pollut Control & Envi, Zhejiang University, Hangzhou, Zhejiang, China.
authors.forename: Li-Lian
authors.initials: LL
authors.lastname: Wen
authors.affiliation: Hangzhou Institute of Environmental Protection Science, Hangzhou, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Yang
authors.affiliation: Department of Environmental Engineering, College of Environmental and Resource Science, Zhejiang University, Hangzhou, China.
authors.forename: Zhao-Xin
authors.initials: ZX
authors.lastname: Zhang
authors.affiliation: Department of Environmental Engineering, College of Environmental and Resource Science, Zhejiang University, Hangzhou, China.
authors.forename: Yang-Yi
authors.initials: YY
authors.lastname: Yi
authors.affiliation: Department of Civil and Environmental Engineering, FAMU-FSU College of Engineering, Florida State University, Tallahassee, FL 32310-6046, USA.
authors.forename: Youneng
authors.initials: Y
authors.lastname: Tang
authors.affiliation: Department of Environmental Engineering, College of Environmental and Resource Science, Zhejiang University, Hangzhou, China; Zhejiang Prov Key Lab Water Pollut Control & Envi, Zhejiang University, Hangzhou, Zhejiang, China; Hangzhou Institute of Environmental Protection Science, Hangzhou, China. Electronic address: zhaohp@zju.edu.cn.
authors.forename: He-Ping
authors.initials: HP
authors.lastname: Zhao
mesh_terms: D001419:Bacteria / Q000378:metabolism*; D001673:Biodegradation, Environmental; D059013:Microbial Consortia / Q000187:drug effects*; D010472:Perchlorates / Q000378:metabolism*; D014241:Trichloroethylene / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D010472:Perchlorates; D014874:Water Pollutants, Chemical; D014241:Trichloroethylene; C494474:perchlorate
keywords: Electron donor; Oxygen; Perchlorate; Reduction; TCE