Polycyclic aromatic hydrocarbons (PAHs) are a class of toxic environmental pollutants that have accumulated in the
environment due to a variety of anthropogenic activities. We isolated 14 different bacteria from various petroleum
contaminates sites, using enrichment technique, and studied for utilization of various hydrocarbons. The bacteria were
capable to grow on various hydrocarbon like diesel, petrol, lubricating oil, toluene, naphthalene and kerosene. The tests
were conducted to detect the biodegradation of diesel, by a monooxygenase biodegradation pathway, and it was observed
that diesel was degraded within 12 hours. Gram negative bacterial isolate RP12 was found to be the best isolate growing
on majority of hydrocarbons and degrading diesel.