کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
20579 | 43181 | 2012 | 6 صفحه PDF | دانلود رایگان |
While multiple theories exist regarding the effect of dissolved oxygen (DO) on the biooxidation of minerals, few studies have been performed the cellular or molecular scale (e.g., genetics) and the mechanism remains unclear. In this paper, the effects of DO concentration on the biooxidation process of refractory sulfide gold ores by Acidithiobacillus ferrooxidans were investigated in the experimental stirred tank bioreactors (STRs). The results indicated that higher biooxidation and cell growth rates were correlated with higher DO concentration. The biooxidation process was restricted at 1.2 ppm DO due to oxygen limitation. Furthermore, the effects of DO on cellular and molecular scale were studied for the first time. The results demonstrated that the oxygen uptake rate (OUR), the Fe2+ oxidation activity and the rus gene expression of A. ferrooxidans all increased with the DO concentration, which might be responsible for the increase of the biooxidation rates with the DO concentration. This study provides insight into the potential impact of molecular-level mechanisms of DO in the biooxidation process of minerals.
► The biooxidation process by Acidithiobacillus ferrooxidans was restricted at 1.2 ppm DO.
► Both the oxidation rate and the cells grew rate increased with the DO concentration.
► The oxygen uptake rate, the Fe2+ oxidation activity and the expression levels of the rus gene of A. ferrooxidans increased with the DO concentration.
Journal: Journal of Bioscience and Bioengineering - Volume 114, Issue 5, November 2012, Pages 531–536