摘要:Polycyclic aromatic hydrocarbons (PAHs) are hydrophobic in nature; they are less soluble in water; so bacteria cannot access or degrade them easily. They are very much toxic to us. A new bacterial strain Bacillus thuringiensis strain NA2 has been isolated from a major petroleum oil contaminated site of India and found to degrade some more toxic members of PAHs like fluoranthene and pyrene. Optimization of this biodegradation has been done by changing different bio-stimulating factors like temperature, pH and addition of glucose as co substrate, Tween 80, H 2 O 2 or organic solvent. The results show an optimum condition at which the bioremediation is very significant. So the bacteria may be employed directly with the contaminated soil or sludge to see its effectiveness.