REDUCTION OF NITROSUBSTITUTED AROMATIC-COMPOUNDS BY THE HALOPHILIC ANAEROBIC EUBACTERIA HALOANAEROBIUM-PRAEVALENS AND SPOROHALOBACTER-MARISMORTUI

The moderately halophilic, obligately anaerobic eubacteria Haloanaerobium praevalens DSM 2228 and Sporohalobacter marismortui ATCC 35420 are able to reduce a variety of nitrosubstituted aromatic compounds at a high rate to the corresponding amines. Compounds degraded included nitrobenzene, omicron-nitrophenol, m-nitrophenol, p-nitrophenol, nitroanilines, 2,4-dinitrophenol, and 2,4-dinitroaniline. Most of these compounds, when added at concentrations of 50 to 100 mg/liter, were completely transformed within 24 h, but at the highest concentrations growth rates were somewhat lowered. Growth of H. praevalens in the presence of C-14-labeled p-nitrophenol showed that the compound was not incorporated by the cells or degraded to acid-volatile compounds.