含氯浸铀尾液对混合浸铀菌株生长动力学影响的研究

以嗜酸性氧化亚铁硫杆菌、氧化亚铁钩端螺旋菌及氧化硫硫杆菌三种混合菌种为受试材料,通过试验分析培养基中pH、Eh、Fe^(2+)和总铁的变化情况,研究氯离子浓度胁迫对混合菌活性的影响。利用[Fe^(2+)]/[Fe^(3+)]的比值及菌种对Fe^(2+)的得率系数对不同Cl^-浓度下细菌的比生长率进行拟合来表征不同Cl^-浓度的浸铀尾液对混合菌生长活性的胁迫效应。结果表明,混合菌对含氯浸铀尾液具有一定的耐受能力。当尾液培养液中Cl^-≤1.0g/L时,Cl^-对混合菌的生长基本没有影响;当Cl^-浓度在1.0~5.0g/L时,混合菌对Fe^(2+)的氧化转化能力开始受到不同程度的影响,影响程度随着Cl^-浓度的增加逐渐增大;当Cl^-=10.0g/L时,混合菌的生长完全受到抑制。

Really active form of fluorine toxicity affecting Acidithiobacillus ferrooxidans activity in bioleaching uranium

In order to determine the mechanism of bacterial tolerance to fluorine,Acidithiobacillus ferrooxidans ATCC 23270 was domesticated and studied under the conditions of different fluorine concentrations and pH values with or without treatment by Proteinase K.The bacterial activities were observed through measuring the changes of solution potentials by platinum electrode with Ag/AgCl reference electrode and the intracellular fluorine was determined by-uorine ion-selective electrode.The results indicated that the tolerance of Acidithiobacillus ferrooxidans ATCC 23270 to fluorine could be obviously improved by domestication,HF was the effective form of fluorine to affect the bacterial activity,and pH increase or concentration change of ions of strong complex ability with fluorine ions in solution could result in false appearance of high fluorine-resistant strain.Some proteins located in cell wall or cell membrane were intimately relative with the bacterial fluorine tolerance.