Pyritic sulphur was removed from coal by growing Thiobacillus ferrooxidans in a 250 ml batch bioreactor. Thiobacillus ferrooxidans grown on sulphur and which was added 5 days after initial inoculation, enhanced the iron solubilization rate by 35% as compared to control (without addition of sulphur-grown cells). About 93% pyritic sulphur was removed in presence of sulphur-grown cells as compared to 77% in the control.