Isolation and description of carbazole-degrading bacteria

Carbazole is a nitrogen heterocyclic compound associated with fossil fuels and their products. Enrichment cultures were established to isolate bacteria able to degrade carbazole and a plate assay was developed to select carbazole-degrading microorganisms from the enrichments. Three different bacterial isolates capable of mineralizing carbazole were obtained. No intermediates of carbazole degradation were detected. The bacteria had a limited substrate specificity; all used benzoate for growth but were unable to utilize the analogues of carbazole, fluorene, or dibenzothiophene.