Two newly isolated aniline-degrading bacterial strains were characterized with regard to their enzyme systems responsible for aniline catabolism. One of them identified as a Rhodococcus sp. metabolized aniline exclusively via the ,3-ketoadipate pathway by means of inducible enzymes. The aniline-degrading enzyme system of the second isolate, presumably a pseudomonad, was shown to consist of an inducible aniline-converting enzyme and constitutive meta-pathway enzymes. Both isolates failed to metabolize monochlorinated anilines in the absence of additional carbon sources. To explain this the ring-cleaving enzymes of both isolates were examined for their substrate specificities. Furthermore, the effect of 4-chlorocatechol on the enzymes catalyzing aniline conversion and catechol oxygenation was investigated.
Microbial degradation of phenyl amides is of environmental relevance. Thus aniline and its derivatives can be found among the waste products of certain chemical industries. I n agricultural soils treated with herbicides of the phenyl amide type (phenylureas, phenylcarbamates, acylanilides) , chloroanilines are formed by microbial transformation of the man-made chemicals. I n some cases the chloroanilines which may react to produce hazardous azocompounds (BARTHA and PRAMER 1970) when accumulated in soil proved to be even more persistent than the applied herbicides.
Soil bacteria capable of utilizing aniline as sole source of carbon, nitrogen, and energy normally fail to degrade chlorinated anilines. However, some of them do metabolize these compounds in the presence of additional energy-providing carbon sources (RE-BER et al. 1979, SUROVTSEVA et al. 1980, YOU and BARTHA 1982).
This paper presents the first results of an investigation concerning microbial degradation of chlorinated anilines. It deals mainly with the characterization of two newly isolated aniline-degrading bacteria and their enzyme systems responsible for aniline catabolism.