Rhodococcus erythropolis was able to selectively oxidize dibenzothiophene (DBT) to sulfate ( ) and 2-hydroxybiphenyl (2-HBP) by metabolic pathway (4S pathway). The existence of restrains further desulfurization by Rhodococcus erythropolis. Addition of the other kind of desulfurization bacterium could remove the restraining by , making the reaction continue to the final products and improving the desulfurization ratio. The high concentration of DBT was reduced from 1.142 to 0.0468 mmol/L by a cooperative desulfurization of the desulfurization bacterium Rhodococcus erythropolis with a hydrolysis aerobic bacterium (No. PYS), which is an expert at degrading . The desulfurization ratio reached 95.9%, which is improved by 32% compared to that without PYS. In a mixture with ratio 1∶9 of water to diesel fuel the sulfur content was reduced from 554 to 306 mg/mL, reaching a 44.8% desulphurization.

Key words: desulfurization by bacterial cooperation, dibenzothiophene (DBT), 2-hydroxybiphenyl (2-HBP), diesel oil