In order to study the possibility of biodegradation of nitrobenzene, 18 strains were isolated from soil polluted long by nitrobenzene and sludge from wastewater treatment plant. These strains can use nitrobenzene as sole carbon source. 5 strains with higher biodegradation ability were selected. At pH 8 and at 35 ℃, the nitrobenzene was removed up to 85% by one strain within 7 d. Fig 1, Tab 3, Ref 7