ASSESSMENT OF BIODEGRADATION OF POLYNUCLEAR AROMATIC COMPOUNDS USING MICROORGANISMS

Abstract

The great increase of populations and industrial development during the last century has increased the demand for hydrocarbons (HCs) like petroleum and its products since they have become a major energy source. The accidental releases of these HCs into the air, water and soil represent potential environmental and health hazards. For this reason, the work presented in this thesis was initiated with an aim to isolate efficient PAH degrading microorganisms and use them in bioremediation of PAH polluted sites. Three aromatic HCs were used, which represent their families; xylene (i.e. representative of monoaromatics), naphthalene (i.e. representative of diaromatics) and anthracene (i.e. representative of polyaromatics). Four isolation samples were brought from Suez, Giza and Helwan cities and were used to isolate either xylene or naphthalene or anthracene degrading microorganisms. The screening of aromatic HC-degrading microbes resulted in the isolation of one hundred and thirty nine microorganisms. The abilities of these microbial isolates to degrade any of the three used c-sources have been investigated on two levels; using individual aromatic HC then a mixture of these three aromatic HCs as a sole c-