Abstract
Previous literature has confirmed that pesticides are posing serious threats to the lives of human beings and animals alike because of their use in agricultural crops. Pesticides have also increased pollution in aquatic and terrestrial environment. In this study, chlorpyriphos degrading bacterial strains were isolated from pesticide contaminated agricultural soils by the selective enrichment method. Bacterial isolates were biochemically characterized for the strain identification. The effect of different environmental factors on optimum growth was also checked. These factors included pH, temperature, and concentration of pesticide. Isolated strains were also ribotyped for identification. Metal resistance profiling was performed for different heavy metals, that is, ZnSO4.7H2O (Zinc sulphate), CdCl2.H2O (Cadmium chloride), CuSO4 (Copper sulphate), and K2CrO4 (Potassium chromate). It was found that strains NW3O and NW3T were sensitive to cadmium except NR2 and NR4, which were resistant at the concentration of 100 and 200 µg ml-1. NR4, NW4 and NW3G were resistant to chromium upto the concentration of 100 µgml-1, while NR2, NW3O and NW3T tolerated 200 µgml-1 of the metal. All the strains were resistant to zinc at different concentrations. NR2 showed maximum resistance to copper by showing growth on all concentrations of the metal. Thin layer chromatography was performed for the detection of different intermediates formed during the degradation of chlorpyrifos. Minimum inhibitory concentration of pesticide was estimated in M9 medium containing chlorpyriphos. The current study resulted in the isolation of efficient chlorpyrifos degrading strains with a wide range of pH and temperature tolerance that can utilize chlorpyrifos upto 700mg/L during lab scale degradation tests (growth on chlorpyrifos supplemented minimal agar and broth).
Highlights
Since before 2500 BC, pesticides are used by humans to protect the crops
Characterization and isolation of Chlorpyriphos degrading Bacteria The bacterial strains were isolated from different agricultural land fields that had earlier history of Chlorpyriphos contamination (Table 1) with the help of careful enrichment techniques
NR2, NR4, NW4, NW3T, NW3G and NW3o were selected which had the capability to use the pesticide as the sole source of energy and carbon
Summary
Since before 2500 BC, pesticides are used by humans to protect the crops. Synthetic pesticides are produced in large quantity since 1940’s. Pesticides target species, including non-target species, bottom sediments, water, food and air. Just 95% herbicides and 98% sprayed insecticides reach a destination [1]. The usage of pesticides for protection of the crops, firstly, recorded about 4500 years ago. Paul Muler discovered DDT as a very effective insecticide in 1993. Pesticides in large amount are used in agricultural activities all over the world that are toxic for humans and for animals. Aquatic and terrestrial ecosystems are contaminated due to inappropriate use of pesticides. Many pesticides are used instantly on different agricultural crops, that increased pollution [2]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
