Genomics Approach to Bioremediation

A range of pollutants are being added to the environment by human activities. Majority of these contaminants are chemically synthesized compounds also termed as xenobiotics. Some of these persist in the environment for longer periods due to presence of structural elements or constituents that do not occur naturally in nature and therefore are resistant to attack by degradative enzymes. Pollutants like nitro aromatics, polycyclic aromatics and biphenyls are degraded relatively within a short period of time or transformed into non-toxic end products owing to microbial degradation. However, highly nitrated and halogenated compounds as well as pesticides and explosives are chemically inert with longer half-lives under native conditions making them recalcitrant. Due to their poor water solubility they tend to enter the food web and are subsequently biomagnified. In addition, many of these pollutants are often metabolized in the mammalian cells resulting in intermediates that are potentially mutagenic or carcinogenic agents (Henschler et al., 2001; Galloway and Handy, 2003). This has led to imposition of prohibition on use of several of these compounds. Apart from this, large quantity of radioactive waste is also generated as a byproduct from nuclear plants generating atomic energy. This bio-hazardous waste is disposed in multiple waste dumping sites worldwide. Currently there is no efficient technology to store this waste safely. Radio nuclides need to be detoxified or effectively immobilized to prevent leaking from the contaminated sites. Ecological disasters resulting from accidental spills of the accumulated toxic waste, not only affects terrestrial ecosystem and marine life but also influences the economy of the area (Samanta et al., 2002; Brim et al., 2003; Regueiro et al., 2007).