title: Perchlorate and nitrate reductase activity in the perchlorate-respiring bacterium perclace.
abstract: The perchlorate (ClO4(-))-respiring organism, strain perclace, can grow using nitrate (NO3(-)) as a terminal electron acceptor. In resting cell suspensions, NO(-) grown cells reduced ClO4(-), and ClO4(-) grown cells reduced NO3(-). Activity assays showed that nitrate reductase (NR) activity was 1.31 micromol min(-1) (mg protein)-1 in (ClO4)- grown cells, and perchlorate reductase (PR) activity was 4.24 micromol min(-1) (mg protein)(-1) in NO3(-) grown cells. PR activity was detected within the periplasmic space, with activities as high as 14 pmol min(-1) (mg protein)(-1). The NR had a pH optimum of 9.0 while the PR had an optimum of 8.0. This study suggests that separate terminal reductases are present in strain perclace to reduce NO3(-) and ClO4(-).
authors.affiliation: Department of Environmental Sciences, 2217 Geology Bldg., University of California, Riverside, CA 92521, USA.
authors.forename: T
authors.initials: T
authors.lastname: Giblin
authors.forename: W T
authors.initials: WT
authors.lastname: Frankenberger
mesh_terms: D001419:Bacteria / Q000254:growth & development / Q000378:metabolism*; D001673:Biodegradation, Environmental; D006863:Hydrogen-Ion Concentration; D050901:Nitrate Reductase; D009565:Nitrate Reductases / Q000378:metabolism*; D009566:Nitrates / Q000008:administration & dosage / Q000378:metabolism*; D009569:Nitric Oxide / Q000008:administration & dosage / Q000378:metabolism; D010084:Oxidation-Reduction / Q000187:drug effects; D010088:Oxidoreductases / Q000378:metabolism*; D010472:Perchlorates / Q000008:administration & dosage / Q000378:metabolism*; D017670:Sodium Compounds / Q000008:administration & dosage / Q000378:metabolism*; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000378:metabolism
chemical_list: D009566:Nitrates; D010472:Perchlorates; D017670:Sodium Compounds; D014874:Water Pollutants, Chemical; D009569:Nitric Oxide; C031068:sodium perchlorate; D010088:Oxidoreductases; D009565:Nitrate Reductases; D050901:Nitrate Reductase; C021777:chlorate reductase