ISOLATION OF SULFUR OXIDATION BACTERIA AND DETERMINING OF MINIMUM INHIBITORY CONCENTRATION (MIC)

The anthropogenic sources of metal contamination can be divided into five main groups: metalliferous mining and smelting, industry, atmospheric deposition, agriculture, and waste disposal. Conventional methods for the removal of the heavy metals ions from environment need high energy and cost. (1) Therefore, much attention has been paid to the removal of metal ions by microorganisms due to its potential applications in environmental protection, and recovery of toxic or strategic heavy metals However, there have been suggesting and testing new methods for remediation of polluted environment based on the organisms. Bioleaching is one of the newest methods for decreasing heavy metals which causes acidification and the solubilization of metals based on the activity of the chemolithoautrothophic bacteria (mainly Thiobacillus ferrooxidans and Thiobacillus thiooxidans) is one of the promising methods for removing heavy metals from contaminated soils and sediment.(3)In contrast, the advantages of bioremediation (e.g. bioleaching) are its relatively low cost, the mild conditions of the process and the subsequent low demand for energy or landfill space compared with conventional technologies.(2)Thus, according to the cases mentioned above the potential of bacteria to remove heavy metals, providing optimum conditions for their growth is essential to select the appropriate Thiobacilli. So investigate the isolating populations and their use in bioleaching is very important that research in this area has led to a major incentive.

Keywords:

Thiobacilli , Zinc , Copper , MICMaterial and method: