Abstract: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.

Key words: fluorine toxicity; bioleaching; uranium ore; Acidithiobacillus ferrooxidans