MICROBIAL TRANSFORMATION OF SELECTED CARBAZOLE DERIVATIVES

A strain of Pseudomonas aeruginosa and another of Aspergillus fumigatu s are found to have the ability to degrade carbazole derivatives. Thes e strains show different specificities for growth on 1- and 3-methylca rbazoles and accumulate formylcarbazoles as end products in low yields . Pseudomonas species degrade 1- and 3-formylcarbazoles to the corresp onding carboxylic acid derivatives which in turn are decarboxylated to carbazole in high yields. This strain also biotransforms the N-acetyl carbazoles (8, 9 and 10) and the respective deacetyl-derivatives (7,2 and 11) are obtained in good yields. This study provides an evidence i n favour of the suggested biotransformation of 3-methylcarbazole to ca rbazole via 3-formylcarbazole and carbazole-3-carboxylic acid in the p lants.