Mixed mesophilic and extreme thermophilic bioleaching were evaluated to remove copper from the molybdenite concentrate.Bioleaching tests were carried out in shake flasks and in a 50-L bioreactor.The shake flask tests were performed with different inoculum size,solids density,pH.and temperature in order to identify optimum conditions.The highest amount of copper elimination,75%was obtained with extreme thermophilic microorganisms(at 12%inoculation,10%solids,65℃and a pH of 1.5).The highest copper elimination by mesophilic microorganisms was 55%(at 12%inoculation,5%solids,30℃at pH 2).The optimum conditions in shake flask tests were applied to 7 days batch tests in a50-L bioreactor.Extreme thermophilic experiment gave the best copper elimination of 60%(at 12%inoculation,10%solids,65℃and pH 1.5).Mesophilic test removed 50%of the copper(at 12%inoculation,10%solids,35℃at pH 2). Mixed mesophilic and extreme thermophilic bioleaching were evaluated to remove copper from the molybdenite concentrate. Bioleaching tests were carried out in shake flasks and in a 50-L bioreactor. The shake flask tests were performed with different inoculum size, solids density, pH and temperature In order to identify the optimum conditions. The highest amount of copper elimination, 75% was obtained with extreme thermophilic microorganisms (at 12% inoculation, 10% solids, 65 ° C and a pH of 1.5). The highest copper elimination by mesophilic microorganisms was 55 % (at 12% inoculation, 5% solids at 30 ° C at pH 2). The optimum conditions in shake flask tests were applied to 7 days batch tests in a50-L bioreactor. Extrem thermophilic experiment gave the best copper elimination of 60% ( at 12% inoculation, 10% solids, 65 ° C and pH 1.5) .Mesophilic test removed 50% of the copper (at 12% inoculation, 10% solids, 35 ° C at pH 2).