Isolation and identification of native sulfuroxidizing bacterium capable of uranium extraction

Abstract

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