Preparation of microbial desulfurization catalysts

A Rhodococcus sp. lawq, a bacterium isolated from the soil cleaving the C-S bond of dibenzothiophene (DBT) via specific pathway, was investigated for cell growth and for its role in desulfurization. Clearly, the end product, 2-hydroxybiphenyl, inhibited the growth of the strain, the synthesis of the desulfurization enzymes, and the activity of the enzymes. The effects of sulfate on the DBT degradation enzymes were examined in the Rhodococcus sp. lawq growth system with DBT; the sulfate served, concurrently, as the sulfur source. The condition of the resting cells that were used in desulfurization, was also studied. The optimal concentration of the resting cells and the reaction conditions were determined. It was documented that there is no difference between desulfurization activity for resting cells cultured with sulfate as the sole sulfur source and that with the mixture of DBT and sulfate as the sulfur source.