Investigations have been carried Out on the iron oxidation rate of Acidithiobacillus ferrooxidans, the bacteria used in bioleaching process. It was observed that the regeneration time of the bacteria is reduced from 168 to 16 11 by repeated sub-culturing, which in turn gave rise to higher iron oxidation rate thus increasing the kinetics of the process. This active strain was utilized for bioleaching of low-grade copper ore by varying two parameters namely, pH and pulp density. It was observed that around 30% of copper could be leached at an initial pH and pulp density of 2 and 20% (m/v) respectively.