SIMULTANEOUS BIODEGRADATION OF NITROBENZENE AND NITRATE BY NATURALLY OCCURING MICROBES IN WETLAND SOILS

The ability of the naturally occurring microbes to reduce nitro group (in nitrobenzene or NB) to aniline under various electron-accepting, (anaerobic) conditions is investigated at bench scale by using enrichment cultures obtained from a shallow soil core collected from a local wetland. Laboratory studies reveal that, after acclimation, the indigenous soil microbes are able to degrade nitrate, and sulfate readily. NB degrades relatively easily under nitrate reducing conditions, and it appears to be affected by the ambient level of nitrate. The addition of yeast extract—the source of carbon, enhances the degradation potential of nitrate, sulfate and nitrobenzene, the other conditions remaining the same. The main focus of this investigation is to study if nitrobenzene and nitrate reduction processes compete with each other as electron acceptors, and if one enhances the degradation of the other, if both are simultaneously present. The degradation potential of NB under sulfate-reducing condition using the wetland soil is also under investigation.