Molecular approaches for biodegradation of polycyclic aromatic hydrocarbon compounds: a review

The waste generated from industrial processes and operations including domestic wastes when treated partially and disposed in soil-water environment enter to lakes, streams, rivers, oceans and other water bodies. The pollutants get dissolved or lie suspended in water or get deposited on soil sediment beds. This results on aquatic and terrestrial pollution which ultimately impact ecosystems causing toxicity to biota and human beings. Industries such as petrochemical, pharmaceutical, insecticides and fertilizers generates the hazardous waste comprising of inorganic and organic compounds. Organic compounds mainly composed polycyclic aromatic hydrocarbons (PAHs), are one of the toxic environmental pollutant. This paper highlights the physicochemical properties, bioremediation treatment and its mechanism for the waste containing PAH. The process of biological remediation depends upon the metabolic action of microbe toward the contaminant which can be achieved by optimum water and nutrient supply and some other limiting factors. The enzymatic degradation gives the molecular approaches for bioremediation. The study also highlighted the molecular approaches which are helpful in revealing functional, structural and communal information about microbial diversity for exploring the routes of degradation pathway of bioremediation process and future scope to bioremediation of PAHs.