The State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, PR China.
J Biosci Bioeng. 2012 Nov;114(5):531-6. doi: 10.1016/j.jbiosc.2012.06.004. Epub 2012 Aug 9.
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 Fe(2+) 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.
虽然有多种理论解释溶解氧（DO）对矿物生物氧化的影响，但很少有研究在细胞或分子水平（例如遗传学）进行，其机制仍不清楚。在本文中，在实验搅拌罐生物反应器（STR）中研究了溶解氧浓度对嗜酸氧化亚铁硫杆菌生物氧化难处理硫化金矿石过程的影响。结果表明，较高的生物氧化和细胞生长速率与较高的 DO 浓度相关。由于氧气限制，生物氧化过程在 1.2 ppm DO 时受到限制。此外，首次研究了 DO 对细胞和分子尺度的影响。结果表明，嗜酸氧化亚铁硫杆菌的耗氧速率（OUR）、Fe（2+）氧化活性和 rus 基因表达均随 DO 浓度的增加而增加，这可能是生物氧化速率随 DO 浓度增加的原因。本研究深入了解了 DO 在矿物生物氧化过程中分子水平机制的潜在影响。
