Denitrogenation of carbazole by a novel strain Bacillus Clausii BS1 isolated from Egyptian Coke

ABSTRACTIn this study, an effective enrichment technique was applied to isolate different bacterial strains with capabilities to denitrogenate carbazole (CAR), as a model compound for nitrogenous polyaromatic hydrocarbons (NPAHs). Twenty-four different CAR-denitrogenating bacterial strains were isolated from mineral coke samples. From all, a Gram +ve bacterial isolate designated BS1 showed a higher biodenitrogenation (BDN) efficiency relevant to the well-known biodenitrogenating bacterium strain Pseudomonas resinovorans CA10, recording 77.15 and 60.66% removal of 1000 ppm CAR with the production of 119.79 and 102.43 ppm anthranilic acid, and 121.19 and 90.33 ppm catechol, as by-products, respectively. BS1 was identified by 16S rDNA gene sequence analysis to be Bacillus clausii BS1 (NCBI GenBank Accession no. KF985981) with a similarity of 99.14%. The CAR-BDN pathway was also elucidated using high-performance liquid chromatography (HPLC) and gas chromatography mass spectrometry analysis (GC/MS), which prov...