title: Growth and denitrifying activity of Xanthobacter autotrophicus CECT 7064 in the presence of selected pesticides.
abstract: The effects of the application of nine pesticides used commonly in agriculture (aldrin, lindane, dimetoate, methylparathion, methidation, atrazine, simazine, captan and diflubenzuron) on growth, CO2 production, denitrifying activity [as nitrous oxide (N2O) released] and nitrite accumulation in the culture medium by Xanthobacter autotrophicus strain CECT 7064 (Spanish Type Culture Collection) (a micro-organism isolated from a submerged fixed-film) were studied. The herbicide atrazine and the insecticide dimetoate totally inhibited growth and biological activity of X. autotrophicus at 10 mg l(-1), while the rest of the tested pesticides delayed the growth of strain CECT 7064 but did not drastically affect the bacterial growth after 96 h of culture. The denitrifying activity of X. autotrophicus was negatively affected by the pesticides application with the exception of fungicide captan. The release of N2O was strongly inhibited by several pesticides (aldrin, lindane, methylparathion, methidation and diflubenzuron), while dimetoate, atrazine and simazine inhibited totally the denitrifying activity of the strain. The effects of the pesticides on denitrifying submerged fixed-film reactor are discussed.
authors.affiliation: Group of Environmental Microbiology, Institute of Water Research, University of Granada, Granada, Spain.
authors.forename: Florentina
authors.initials: F
authors.lastname: Sáez
authors.forename: Clementina
authors.initials: C
authors.lastname: Pozo
authors.forename: Miguel Angel
authors.initials: MA
authors.lastname: Gómez
authors.forename: Maria Victoria
authors.initials: MV
authors.lastname: Martínez-Toledo
authors.forename: Belén
authors.initials: B
authors.lastname: Rodelas
authors.forename: Jesús
authors.initials: J
authors.lastname: Gónzalez-López
mesh_terms: D002245:Carbon Dioxide / Q000378:metabolism; D009609:Nitrous Oxide / Q000378:metabolism*; D010575:Pesticides / Q000494:pharmacology*; D014874:Water Pollutants, Chemical / Q000378:metabolism*; D020584:Xanthobacter / Q000187:drug effects* / Q000254:growth & development* / Q000378:metabolism
chemical_list: D010575:Pesticides; D014874:Water Pollutants, Chemical; D002245:Carbon Dioxide; D009609:Nitrous Oxide