Abstract: Uranium ore often has a high fluorine content, which will enter the bacteria solution during uranium leaching. Fluorine ions are an important factor depressing the bacteria growth and affecting the acid production ability of bacteria. The test shows that when F- amounts below 16 mg/L, Thiobacillus Thiooxidans can grow well in four days; when F- reaches 30 mg/L, its growth period will exceed 15 days. When F- is below 8 mg/L in the bacteria solution, the acid production ability of bacteria will be little affected, but when F- reaehes up to 16 mg/L, it will be greatly affected. By domestication, the fluorine resistance of Thiobacillus Thiooxidans can be raised to endure a fluorine concentration of 40 mg/L in uranium leaching.

Key words: Thiobacillus thiooxidans,   , Fluorine resistance,  , Domestication