Aniline aerobic degradation

Chlorinated anilines are aerobically degraded, by both soil and sewage microorganisms, the monochloro-compounds more readily than the dichloro-derivatives. Chloroanilines are formed in soil as part of the degradation process of the substituted urea herbicides [70]. An alternative pathway is the production of substituted azobenzenes, by dehydrogenation-condensation involving two amino groups. 

Nitroaromatics are slowly degraded by microorganisms both under aerobic and anaerobic conditions, and the metabolic steps involved in the degradation have been poorly documented until now. Two major catabolic pathways are involved in the degradation of nitroaromatics (Figure 1) [23]. In the first pathway, tiie nitro group is reduced to an aniline intermediate, which is further degraded to ammonimn ion and catechol [5,24-28]. 

Like aniline, TAT is an electron-rich compound and should be readily oxidized by aerobic microorganisms. In the presence of O2, particularly when heavy metal ions (e.g. Mn ) are present, TAT undergoes rapid autooxidation to generate dark polymers. These abiotic reactions prevent productive metabolism of TAT by aerobic microorganisms. A promising yet unexploited possibility is the degradation of TAT under denitrifying conditions (30), because TAT is chemically not oxidized by nitrate (O. Dickel, personal communication). 

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