Bacteria capable of utilizing naphthalene, as their sole source of carbon and energy forgrowth were isolated from three different sites in warangal,Andhra Pradesh. By standard bacteriologicalmethods, these bacteria were characterized taxonomically as belonging to the genus Pseudomonas,Burkholderia or Actinomycetes. Two of the isolates, which showed the highest growth during screeningas demonstrated by an increase in their optical densities at 600 nm and named as NITWDBT1 andNITWDBT3.In isolate NITWDBT1, the lowest optimum growth of 0.189 at 600 nm was observed whenthe level of anthracene was lowest (50 ppm); while the highest optimum growth of 0.578 was recordedwhen the level of anthracene was highest (300 ppm). Similarly, the lowest optimum growth in isolateNITWDBT3 was 0.173 at anthracene level of 50ppm, while the highest was 0.380 when the level ofanthracene was 250 ppm (OD600). These two isolates were identified as Pseudomonas aeruginosa andBurkholderia cepacia respectively, were also able to grow in anthracene and carbazole, but not very muchso in 2,4-dichlorophenol and D-camphor. The isolates showed a concentration-dependent growth in allthe compounds they were grown. There were visible changes in the colour of the growth medium of theisolates during their incubation, suggesting the production of different metabolites. There were alsochanges in their medium pH during growth. These studies demonstrate the possession by the bacterialspecies of novel degradative systems
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