Abstract: An excellent strain named T.f₆ was isolated and screened, the dose and other condition for the UV-induced mutagenesis were studied and the richened positive mutant m⁺ T.f₆ was applied in the column leaching of copper-containing sulfides. The results show that T.f₆ is characterized by rapid oxidation of ferrous ion and cupric sulfide, high tolerance of toxic ion and short generation time. The best mutagenic effectiveness can be obtained under the dose of low kill rate of UV and low temperature treatment, under which the best richened m⁺ T.f₆ can be shortened 1.4h.It was shown by the column leaching of copper that the leaching rate can be enhanced by at least 11% compared with the original one by the mutants.

Key words: Thiobacillus ferrooxidans; mutagenesis; bacterial leaching