Operational evaluation of sulfur oxidizing bacteria yield isolated from copper mine soil and their molecular identification based on 16S rRNA sequence

One ways to increase the operational efficiency of leaching metals from sulfide minerals is using efficient species of sulfur oxidizing bacteria in metal mining. Thus, the aim of this study was to isolate and identify sulfur oxidizing bacteria from soils of Sarcheshmeh copper mine (Kerman, south of Iran) and to survey their operation in sulfur oxidation. After enrichment, samples were purified and then isolates were identified based on their morphological characteristics and phylogenic techniques. Subsequently, three sulfur-oxidizing strains which belonged to Acidithiobacillus sp and Sulfobacillus sp were isolated and identified. Of these three, strain 184, with 95% similarity to Acidithiobacillus ferridurans was selected as the superior strain due to higher growth rate (change of 2 value pH and 385 mg S/L during 2 weeks) in the synthetic mineral medium containing sulfur which can now be used as an applicable strain in bioleaching of copper metal.