Nitroaromatic compounds are used as raw materials for synthesis of not only plastics, pesticides, pharmaceuticals, but also for explosives, solvents, paper etc. p-Nitrophenol (PNP) is one of the nitroaromatic chemical that has a hydroxyl group and a nitro group which is used as transitional for the synthesis of number of organophosphate pesticides, azo dyes, etc. According to the U.S. EPA PNP is a priority pollutant. Enzymes that can degrade the PNP are secreted by soil micro-organisms, of which oxygenases are the key enzymes for aerobic biodegradation of aromatic compounds for the complete mineralization of these compounds. Pseudomonas sp., isolated from farm soil is one of the many micro-organisms that have the ability to produce such enzyme.

Keywords : P-Nitrophenol; biodegradation; oxygenases; isolation; Pseudomonas sp.