Identification of Thiobacillus ferrooxidans strains based on restriction fragment length polymorphism analysis of 16S rDNA

The 16S rDNA sequences from ten strains of Thiobacillus ferrooxidans were amplified by PCR. The products were compared by performing restriction fragment length polymorphism (RFLP) analysis with restriction endonucleases Alu I, Hap II, Hha I, and Hse Ill. The RFLP patterns revealed that T. ferrooxidans could be distinguished from other iron- or sulphur-oxidizing bacteria such as T: thiooxidans NB1-3, T: caldus GO-1, Leptospirillum ferrooxidans and the marine iron-oxidizing bacterium strain KU2-11. The RFLP patterns obtained with Alu I, Hap II, and Hae III were the same for nine strains of T: ferrooxidans except for strain ATCC 13661. The RFLP patterns for strains NASF-1 and ATCC 13661 with Hha I were distinct from those for other T: ferrooxidans strains. The 16S rDNA sequence of T: ferrooxidans NASF-1 possessed an additional restriction site for Hha I. These results show that iron-oxidizing bacteria isolated from natural environments were rapidly identified as T: ferrooxidans by the method combining RFLP analysis with physiological analysis.