Biodegradation of nitrobenzene in a lysogeny broth medium by a novel halophilic bacterium Bacillus licheniformis

摘要

The Bacillus licheniformis strain YX2, a novel nitrobenzene-degrading halophilic bacterium, was isolated from active sludge obtained from a pesticide factory. Strain YX2 can withstand highly acidic and alkaline conditions and high temperatures. Degradation of nitrobenzene (200 mg L~(-1)) by YX2 exceeded 70% after 72 h in lysogeny broth medium (pH 4-9). Under optimal degradation conditions (33 ℃, pH 7 in LB medium) YX2 degraded 50,100, 200, and 600 mg L~(-1) nitrobenzene within 36,36,72, and 156 h, respectively. Even in the presence of benzene, phenol or aniline, strain YX2 efficiently degraded nitrobenzene. Furthermore, strain YX2 completely degraded 600 mg L~(-1) nitrobenzene in 7% NaCl (w/w). Thus, our data show that strain YX2 may have promise for removing nitrobenzene from complex wastewaters with high salinity and variable pH.