نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشجوی دکتری بیوشیمی، دانشگاه پیام نور واحد تهران شرق، تهران، ایران

2 استاد، گروه زیست شناسی، دانشگاه پیام نور، تهران، ایران

چکیده

باکتری Acidithiobacillus ferrooxidans از مهمترین باکتری­های شرکت کننده در فرآیند فروشویی میکروبی اورانیوم بوده که در آن، آهن فریک به عنوان یک پذیرنده الکترون عمل کرده و U+4 نامحلول را به U+6 محلول، تبدیل می­کند. در مطالعه حاضر، باکتری­ دخیل در فرآیند فروشویی میکروبی اورانیوم با استفاده از اشعه UV در سه دوز 60، 120 و 180 ثانیه جهش داده شد. باکتری ها در حضور غلظت های مختلف سنگ اورانیوم قرار داده شده و بازده فروشویی میکروبی آنها بررسی گردید. سپس، در توالی های 24 ساعته میزان استخراج اورانیوم، تغییرات pH و Eh آنها اندازه گیری شد.نهایتا، بیان ژن rus باکتری Acidithiobacillus ferrooxidans جهش یافته و وحشی در حضور چگالی پالپ های مختلف با استفاده از روش Real time PCR مورد بررسی قرار گرفت. نتایج حاصل از آزمایشات نشان می­دهد تغییرات Eh، pH و استخراج اورانیوم در فرآیند فروشویی میکروبی توسط باکتری های جهش یافته و وحشی با چگالی پالپ بالای سنگ نسبت به باکتری­های کشت یافته با چگالی پالپ پائین­تر به تأخیر افتاده است. نتایج حاصل از بررسی بیان ژن rusباکتری جهش یافته و وحشی در غلظت های مختلف کانسنگ نشان داد که جهش و غلظت سنگ بر روی بیان ژن مذکور موثر بوده است. به عبارتی دیگر می توان اذعان داشت که تغییرات بیان ژن rus عامل تاثیر گذاری بر فعالیت باکتری در استخراج اورانیوم با افزایش چگالی پالپ، می باشد.در تحقیق حاضر، باکتری بومی تا 50٪ کانسنگ معدن سازگار شده که مقدار بسیار قابل توجهی در فرایند فروشویی میکروبی اورانیوم می باشد.

کلیدواژه‌ها

موضوعات

عنوان مقاله [English]

Evaluation of Acidithiobacillus ferrooxidans rus gene expression treated with UV radiation in uranium bioleaching process

نویسندگان [English]

  • Malus Sheydaie 1
  • Reza Haji Hosseini 2

1 PhD. Student of Biochemistry, Faculty of Science, Payame Noor Univercity, Tehran, Iran

2 Biology Departments, Faculty of Science, Payame Noor Univercity, Tehran, Iran

چکیده [English]

Acidithiobacillus ferrooxidans is the main bacteria involved in the uranium bioleaching in which the ferric ion acts as an electron acceptor and converts insoluble U+4 to soluble U+6. The oxidation process involved the electron transport chain which would occur through several periplasmic carriers. In this research, the bacterium involved in uranium bioleaching process was mutated using UV radiation at doses of 60, 120 and 180 seconds. Mutant and wild bacteria were placed in the presence of various concentrations of uranium ore (5, 10, 15, 25 and 50 %) and their bioleaching yields were examined. Then, uranium extraction, variation of pH and Eh were measured in the 24 hour intervals. Finally, rus gene expressions of mutant and wild Acidithiobacillus ferrooxidans in the presence of various uranium ore were analyzed using Real time PCR method. The results showed that, the changes of Eh, pH and uranium extractions at bioleaching process by mutant and wild bacteria have been delayed in the presence of high pulp density in compare with lower one. The results of rus gene expressions in mutant and wild bacteria in the presence of ore different concentrations showed that mutations and ore concentration has been effective on the expression of this gene. It should be noted that, in the present project, the native bacteria were adapted to 50% uranium ore that is very significant at uranium bioleaching process.

کلیدواژه‌ها [English]

  • Uranium bioleaching
  • Acidithiobacillus ferrooxidans
  • rus gene
  • Real time PCR
 
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