تاثیر شرایط کشت یک سویه جدید تیوباسیلوس در اکسیداسیون آهن

عنوان انگليسی

Effects of Culture Conditions of Fe-oxidation in a Newly-isolated Thiobacilus ferrooxidans

خلاصه انگلیسی

Background & Objectives: Bioleaching is a process utilizing microorganisms to extract heavy metals from ores. This process can be carried out by several groups of bacteria but the most commonly-used one is Acidothiobacillus. The main aimof this research was to isolate the local bacteria from Meydook ore in order to achieve the best strain. The effect of culture medium, temperature and pH on bioleaching process was also investigated. Methods: The mineral 9-K medium was utilized for bacterial growth and leaching. The samples of ore were treated with 0.1 N sulfuric acid then, 70 ml of resulting liquid was added to 200 ml of K-9 medium and incubated at 30° C. DNA extraction and PCR DNA was extracted using DNA extraction kit. The spacer region between 16s and 23s genes was amplified by PCR using forward and reverse primers of 27F and 1492R. Optimization of the medium Temperature, pH and culture medium components were optimized by statistical Methods and analyzed by Design-expert-6.0.10 software. Results: The indigenous bacterium Acidothiobacillus ferrooxidans was registered in NBCI gene bank with FR772290 number. Furthermore, the optimum culture conditions were obtained as follows: (NH4)2SO4 (1.5 g/L), KH2PO4 (0.34 g/L), MgSO4 (0.34 g/L), KCl (0.2 g/L), Ca(NO3)2 (0.01 g/L), FeSO4 7H2o (25g/L), pH (2.5), temperature (35 °C). Conclusion: It was demonstrated that the most effective factors on Fe-oxidation process by the bacterium were temperature , pH and the amount of FeSO4 7H2o.

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