DefinePK

Abstract

  Background:  Cypermethrin is a Synthetic Pyrethroid (SP) having widespread applications in agriculture and industrial sector especially in sheep dip formulations and tanneries. Rhizoremediation offers a sustainable, environment-friendly and cost-effective means to carry out remediation of contaminated soils. Methods: Six bacterial strains were screened out and characterized at various doses of cypermethrin, heavy metal salts and antibiotics. The optimum growth conditions were determined for these bacterial isolates. The degradation of cypermethrin was confirmed through the growth of bacteria on minimal media (BHB) with cypermethrin and thin layer chromatographic analysis; retention factor values (R f ) were calculated and compared with standard R f values. Results: Growth curve experiments revealed that three bacterial isolates were able to grow in the presence of cypermethrin. Tolerance to the high concentration of heavy metal salts (300µgmL -1 ) and resistance towards different antibiotics was observed in all three bacterial isolates indicating a positive correlation between pesticide degradation and tolerance to metals and antibiotics. Bacterial strains A-C 1 and B-B 2 were identified as Xanthomonas maltophilia and B-C 2 as Acinetobacter sp. Cypermethrin degradation occurred concomitant with bacterial growth reaching an optical density (OD 600 ) up to 0.869. Conclusion: Microbes present in rhizosphere have potential to mineralize the pesticides. A significant biodegradation of the cypermethrin was observed based on above mentioned lab parameters. These results paved the way for designing a multi-resistant bacterium that can be used to reverse the altered environment.