Molecular characterization of Acidithiobacillus ferrooxidans strains isolated from different environments by three PCR-based methods

WU Xue-ling(吴学玲)^{1, 2}, LIU Li-li(刘莉莉)^{1, 2}, ZHANG Zhen-zhen(张真真)^{1, 2}, DENG Fan-fan(邓凡凡)^{1, 2}, LIU Xin-xing(刘新星)^{1, 2}

(1. Key Laboratory of Biometallurgy of Ministry of Education (Central South University), Changsha 410083, China;
2. School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China)

Abstract:PCR-based DNA fingerprinting, REP-PCR (repetitive element PCR), RAPD (randomly amplified polymorphic DNA) and 16S rDNA sequence analyses were used to characterize 23 Acidithiobacillus ferrooxidans strains isolated from different environments. (GTG)₅ and BOXA1R primer were selected for REP-PCR. Twenty arbitrary primers were used for RAPD to acquire DNA profiles from A. ferrooxidans. Both RAPD and REP-PCR produce complex banding patterns and show good discriminatory ability in differentiating closely related strains of A. ferrooxidans. The strains are clustered into 4 or 5 major groups and reveal genomic diversity using (GTG)₅-PCR, BOX-PCR and RAPD analysis. Phylogenetic tree based on 16S rDNA sequences of 23 strains and related strains shows that they are clustered into two distinct groups. Twelve strains are highly related to a new Acidithiobacillus named Acidithiobacillus ferrivorans. The results indicate that PCR-based methods are effective in revealing genetic diversity among A. ferrooxidans.

Key words:Acidithiobacillus ferrooxidans; repetitive element PCR (REP-PCR); randomly amplified polymorphic DNA (RAPD); 16S rDNA sequence analysis; genetic diversity