eng Oriental Scientific Publishing Company Biosciences Biotechnology Research Asia 0973-1245 2013-06-28 10 1 10.13005/bbra/1090 9876 article H.N. Nassar 1 N.Sh. El-Gendy 1 M.A. Abo-State 2 Y.M. Mostafa 1 H.M. Mahdy 3 S. A. El-Temtamy 1 Egyptian Petroleum Research Institute, Nasr City, Cairo, Egypt. National Centre for Radiation Research and Technology (NCRRT), Cairo, Egypt. Botany and Microbiology Department, Faculty of Science, Al-Azhar University, Cairo, Egypt. In this study, an effective enrichment technique was applied to isolate different bacterial strains with capabilities to utilize dibenzothiophene (DBT) as a model compound of polyaromatic sulfur heterocyclic compounds (PASHs). Twenty-eight different desulfurizing bacterial strains were isolated from a mineral coke sample with sulfur content of 3.8%. Only nine of them showed the ability to utilize DBT as a sole-sulfur source through the 4S-pathway without altering its hydrocarbon skeleton. From all; a Gram +ve bacterial isolate designated C19 showed a higher biodesulfurization (BDS) efficiencyrelevant to the well-known biodesulfurizing bacterium strain R. erythropolis IGTS8, recording 66.85% and 50% removal of 1000 ppm DBT with the production of 31.98 and 31.34 ppm 2-hydroxybiphenyl (2-HBP), as a dead end product, respectively. C19 was identified by 16S rDNA gene sequence analysis to be Brevibacillus invocatus C19 (NCBI Gene Bank Accession no. KC999852) with similarity of 99.05%. BDS of different PASHs was also studied and Brevibacillus invocatus C19 showed good BDS capabilitiescompared to those of IGTS8. https://www.biotech-asia.org/vol10no1/desulfurization-of-dibenzothiophene-by-a-novel-strain-brevibacillus-invocatus-c19-isolated-from-egyptian-coke/ Biodesulfurization; Dibenzothiophene; 4S-pathway; Thiophenic compounds; 16s rDNA