Summer Research Fellowship Programme of India's Science Academies

Isolation and Identification of Bacteria Degrading Polycyclic Aromatic Hydrocarbons


Kamaraj College of Engineering and Technology, Tamilnadu


Professor and Chairperson, Board of Studies, Bacterial Discovery Laboratory, Centre for Environment, Institute of Science and Technology, JNTU, Hyderabad


Polycyclic Aromatic Hydrocarbons (PAHs) are ubiquitous and toxic pollutants that are considered to be an alarming environmental threat. They are multiple fused aromatic compounds with two or more intertwined benzene rings and are generated during the incomplete combustion of organic compounds such as fossil fuels. For example, crude oil spills in sea which contains several PAH's have resulted in a major marine environmental pollution. The main objective of this research is to use a suitable approach for the isolation of bacteria capable of degrading different PAHs from the affected environment. Bioremediation is a dominant degradation process for many organic pollutants. In this process, microorganisms such as bacteria and fungi are used to remove environmental pollutants. This natural strategy uses low chemicals and energy and is cost-effective and eco-accommodating. In this work, bioremediation has been employed using bacteria for the degradation of toxic PAHs present in the polluted environment. However, bioavailability of PAH is limited because of its hydrophobic nature and high adsorbing potential. Hence, a chemical surfactant which is not an inhibitor of the bacterial metabolism was opted to emulsify the components present in the crude oil (mixture of various simple and complex hydrocarbons). The phases involved in the experiment are enrichment, isolation, purification and degradation studies of PAH degrading bacteria. Biebl & Pfennig's medium was used for the isolation of bacteria present in the crude oil and crude oil itself is supplemented as a sole carbon source. Colony characteristic studies and microscopic observation were done for the isolated strains. Spectrophotometric analysis will be done for determination of the degradation efficiency of the enriched strains.

Keywords: PAHs, Organic compounds, Marine environment, Bioremediation, Crude oil, Chemical surfactant, Isolation of PAHs degrading bacteria

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