ICAR Research Data Repository for Knowledge Management

Dichlorodiphenyltrichloroethane (DDT) is the first synthetic compound used against pests. Though it was first synthesised by Zeidler, the noble prize for its activity against insects especially against body lice and in control of typhus fever was awarded to Dr. Paul Muller. After the discovery that DDT can be used against insects, it was extensively used by almost all the countries for both agriculture as well as health programs. Later, it was
discovered that DDT was responsible for many environmental problems viz. thinning of the eggshells in many birds especially Falcons, bringing it under the endangered category, being one among the first few hazards noticed.
Today it is one of the suspect culprits for hormonal imbalance and even cancer. Its main advantage, when initially used, was its effectiveness on wide
variety of insects, leading to a large-scale application on pests. However, the persistency has been now the main cause of concern to the environmentalists. Residues of DDT have been detected in soil, water and also in air. Through food chain they enter the human body causing health
hazards. There have been many efforts to remediate DDT- contaminated sites. DDT has also been shown to undergo transformation and form other compounds that are either dead
end metabolites or even more toxic than DDT. Microorganisms have been shown to mineralise many xenobiotic aromatic compounds. Microorganisms can be used to remove DDT from soil and water with very low or no accumulation of intermediary toxic metabolites. Microbial remediation is the
most safe and cost effective way of remediation towards a cleaner and safer environment. With the above concepts in mind, attempts were made to isolate some microbes that could degrade DDT effectively. Four bacterial strains were
obtained during long-term enrichment of DDT-contaminated soil and water. Various parameters of DDT degradation were studied. Attempts were also made to decipher the biodegradative pathway. A few catabolic genes were
attempted for identification.