Journal of
Toxicology and Environmental Health Sciences

  • Abbreviation: J. Toxicol. Environ. Health Sci.
  • Language: English
  • ISSN: 2006-9820
  • DOI: 10.5897/JTEHS
  • Start Year: 2009
  • Published Articles: 217

Full Length Research Paper

Effect of some pesticides on growth, nitrogen fixation and nifgenes in Azotobacter chroococcum and Azotobacter vinelandii isolated from soil

Kasim Abass Askar
  • Kasim Abass Askar
  • School of Biomedical and Biological Sciences, University of Plymouth, Plymouth, PL4 8AA, United Kingdom
  • Google Scholar
Aras Mohammed Khudhur
  • Aras Mohammed Khudhur
  • Soil and Water Department, College of Agriculture, University of Salahaddin, Erbil, Iraq
  • Google Scholar

  •  Accepted: 30 July 2013
  •  Published: 30 September 2013


This study was designed to evaluate the effects of three pesticides (Imazetapir, Dimethoate and Bayleton 50) at the recommended concentration (in the field), on the growth of pure cultures ofAzotobacter chroococcum and Azotobacter vinelandii, on the amount of fixed nitrogen and nifgenes. Herbicide Imazetapir had no negative effect on nitrogen fixing bacteria, while Dimethoate and Bayleton 50 exhibited inhibitory effect on growth. Same effects were obtained on fixed nitrogen obtained when treated with studied pesticides. nifH1, nifH2, nifH3, nifU and nifV from A. chroococcum, and nifH, nifK, nifD, and nifM gene in A. Vinelandii were lost when pots were cultivated with wheat and treated with both Dimethoate and Bayleton 50, therefore, be deemed highly susceptible to them. While herbicide did not affect the nif genes, the bands on gel electrophoresis appeared as normal sample.


Key words: Azotobacter chroococcumAzotobacter vinelandii, fungicide (Bayleton 50), herbicide (Imazetapir), insecticide (Dimethoate).