Objectives: The objective of this study was to investigate the possible presence of Ferrooxidant bacteria, in particular Thiobacillus and Leptospirillum, and to evaluate their contribution in the leaching of copper ores. Methodology and Results: We selected two types of samples from the leaching solution: pulp filtrate and pulp. Each sample was plated on thioglycholate resazurin medium and subcultured on blood agar under anaerobic conditions. Neither...