Abstract: Acidithiobacillus ferrooxidans strains were isolated from mineral wastes in 2 copper coal mining areas in the modified 9K-culture medium containing ferrous ions as the sole source of energy. The isolated bacteria were added to the copper coil mining samples in leaching mini-plants. The total Cu content of samples, which measured by atomic absorption, decreased to 66.7% in sterilized samples and to 20% in non-sterilized samples. The optimum decrease of total Cu content occurred in pH 2. There was a 46.7% increasing in the copper extraction by synergistic activity of natural ferrous oxidizing microorganisms and the isolated bacteria which added to the area of the experiment. The result obtained via comparison of sterilized and non-sterilized samples. The acceleration of copper dissolution showed the advantage of mixed cultures of iron and sulfur oxidizing microorganisms in non-sterilized minerals in low pH values for copper extraction.