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 a mplified by PCR. The products were compared by performing restriction fragm ent length polymorphism (RFLP) analysis with restriction endonucleases Alu I, Hap II, Hha I, and Hse Ill. The RFLP patterns revealed that T. ferrooxid ans could be distinguished from other iron- or sulphur-oxidizing bacteria s uch as T: thiooxidans NB1-3, T: caldus GO-1, Leptospirillum ferrooxidans an d the marine iron-oxidizing bacterium strain KU2-11. The RFLP patterns obta ined with Alu I, Hap II, and Hae III were the same for nine strains of T: f errooxidans except for strain ATCC 13661. The RFLP patterns for strains NAS F-1 and ATCC 13661 with Hha I were distinct from those for other T: ferroox idans strains. The 16S rDNA sequence of T: ferrooxidans NASF-1 possessed an additional restriction site for Hha I. These results show that iron-oxidiz ing bacteria isolated from natural environments were rapidly identified as T: ferrooxidans by the method combining RFLP analysis with physiological an alysis.