Metabolism of compounds with nitro-functions by Klebsiella pnuemoniae isolated from a regional wetland

Metabolism of nitroaromatic compounds by a Klebsiella pneumoniae isolated from a regional wetland was studied. When it was grown with nitrophenol as the sole nitrogen source, the isolate had the metabolic capability of transforming nitrophenol to phenol; however, it did not use nitrophenol as the sole carbon source. The metabolic pathway showed that the K. pneumoniae reduced the nitro group to an amino group forming aminophenol as a major metabolite. This aminophenol was oxidatively deaminated to phenol. For every mole of nitrophenol metabolized, 1 mol of phenol was produced and the phenol did not undergo further metabolism. The isolate also used several other nitroaromatic compounds including nitrotoluenes and nitrobenzenes as its nitrogen source. Even though this organism did not degrade the nitroaromatics completely, it may be useful in degrading nitroaromatics in contaminated soil and water containing other aromatic degraders in a syntrophic condition in nature.