The microbial degradation of dibenzothiophene (DBT) and other organosulphur compounds such as thiophene-2-carboxylate (T2C) is of interest for the potential desulphurization of coal. The feasibility of degradation of DBT and T2C by Pseudomonas putida and other bacteria was analysed. Pseudomonas putida oxidized sulphur from DBT in the presence of yeast extract, but it did not when DBT was the sole source of carbon.