REDUCTION OF AROMATIC NITRO-COMPOUNDS IN ANAEROBIC ECOSYSTEMS

The moderately halophilic anaerobic eubacteria Haloanaerobium prevalen s and Sporohalobacter marismortui are able to reduce p-nitrophenol and a variety of other nitrosubstituted aromatic compounds at a high rate to the corresponding amines. p-Nitrophenol was not incorporated by th e cells or degraded to acid-volatile compounds. Other compounds transf ormed included nitrobenzene, o-nitrophenol, m-nitrophenol, nitroanilin es, 2,4-dinitrophenol, and 2,4-dinitroaniline. Also sheep rumen fluid was found to transform p-nitrophenol and a number of other nitroaromat ic compounds at a high rate. At least 50% of the p-nitrophenol transfo rmed was recovered as p-aminophenol. The findings suggest that anaerob ic transformation of nitroaromatic compounds may be widespread in the bacterial world.