Dibenzothiophene is degraded to 3-hydroxy-2-formyl benzothiophene by various bacteria, including a strain of Pseudomonas putida that also forms dibenzothiophene sulfone via an alternate pathway. By using these end products as substrates, mixed enrichment cultures that could degrade 3-hydroxy-2-formyl benzothiophene and dibenzothiophene sulfone with the formation of CO2 were established.