International Journal of Environmental Engineering
Author(s) : ELIZABETH MARY JOHN, JISHA M.S., SHARREL REBELLO
Widespread and indiscriminate use of Chlorpyrifos (CP) - an organophosphate pesticide, leads to severe environmental problems. It poses a great threat to different trophic levels of the ecosystem from soil microorganisms to human beings. As the risk of their off-site migration pose health risk to non-target organisms, it is essential to remove this pesticide from their point source of contamination. The current research paper attempts to develop a bacterial consortium capable of remediating CP effectively. The degradatory efficiency of thirteen morphologically different soil bacterial isolates obtained by selective enrichment on mineral medium containing CP (25ppm) or Trichloro2- pyridinol (TCP- antimicrobial byproduct of CP degradation) (25 ppm) as sole source of carbon and nitrogen was investigated for five days. The isolates were equally capable of degrading TCP compared to CP. Using these isolates different bacterial consortia were developed and the consortium C2 (S5, S6, S12) was efficient and showed 95.38±0.02 % of degradation of CP (25 ppm) in three days. The efficiency of the consortium to mineralize CP was investigated under different culture conditions. The study revealed that the consortium could transform CP to non-toxic products. Immobilisation of developed consortium was done and rate of CP degradation using immobilized system in presence of inorganic fertilizer (N: P: K) and coir pith was investigated. The obtained results demonstrated that the immobilized consortium could be recommended for usage in biobeds as a viable alternative to prevent CP dissipation in the environment.