ISOLATION AND IDENTIFICATION OF NATIVE SULFUROXIDIZING BACTERIUM CAPABLE OF URANIUM EXTRACTION

Bioleaching is the extraction of metals from their ores through the use of microorganisms. In this process, the use of native bacteria leads to achieve more yields of metals. So, in the present study, native sulfur-oxidizing bacterium in potentiality of uranium extraction was isolated from Ghachin mine in Iran and identified by partial gene sequencing. For this purpose, the water samples were collected from Ghachin mine and cultivated in Starkey medium. In following, the isolate was inoculated into individual Starkey plates and incubated until the colonies indicating the purified bacterium appeared. Then, the identification was carried out based on phenotypic characteristics and 16s rDNA sequencing. After that, bioleaching of uranium experiments carried out using uranium ore at 2.5 and 5% pulp densities. The result showed that after 15 days of incubation, the bacteria in the fresh samples was grown. Following 5-7 days of the plateʹs incubation, we obtained the single purified colonies of the bacteria. On the basis of 16s rDNA nucleotide sequencing, the bacteria showed 99.71% similarity to Acidithiobacillus ATCC 19377. Besides, the bioleaching experiments indicated that the bacterium is capable of uranium extraction in 2.5 and 5% pulp densities during 3 and 5 days. In conclusion, in this study, for the first time, we isolated the native sulfur-oxidizing bacterium capable of uranium extraction, from uranium mine of Gachin in Bandar Abbas, Iran.