Influence of different Fe sources and concentrations on formation of magnetosomes in Acidithiobacillus ferrooxidans

The whole genome of strain Acidithiobacillus ferrooxidans ATCC 23270 was analyzed by bioinformatics and some homolog genes of functional ones in magnetotactic bacteria were available. To obtain further knowledge of the magnetosomes formation mechanisms of Acidithiobacillus ferrooxidans in response to different Fe sources and concentrations, temporal gene expression profiles of mpsA, magA, mamB and thy were examined by using Real-time quantitative reverse transcription-PCR. The microbial formation of magnetosomes and magnetotaxis was also studied under different Fe2+ concentration. The results indicated that ORF numbers of 1622, 0276, 1124 and 2572 of the ATCC 23270 were homologous with mpsA, thy, magA and mamB genes in magnetotactic bacteria. The expression levels of mpsA, magA and mamB were directly related to ferrous concentration, and the highest expression level at 150–200 mmol/L ferrous was gained. The number of magnetosomes in ATCC 23270 and the magnetotaxis of cells were significantly related to the expression level of these three genes, suggesting that these genes were related with the iron transport during the process of magnetosome formation in A. ferrooxidans.