Research Of Gene About Formation Of Magnetosomes In Acidithiobacillus Ferrooxidans

The magnetosome as an ideal kind of bio-nano-magnetic material that attracts the most attention, in recent years. The researchers in this group discovered the fact that the Acidithiobacillus ferrooxidans could synthesize intracellular electron-dense magnetic particles and this study researched the formation of magnetosomes in Acidithiobacillus ferrooxidans. In addition, the whole genome of of the type strain Acidithiobacillus ferrooxidans ATCC 23270 was analysized by bioinformatics and some homolog genes of functional ones in magnetotactic bacteria were available.This study obtained that proteins incoded by ORFs 1622,0276,1124,2572 were homologous with MpsA,Iron Reductase (Thy),MagA,MamB in magnetotactic bacteria, respectively. To obtain further knowledge of the magnetosomes formation mechanisms of A.ferrooxidans ATCC 23270 in response to different concentration of FeSO₄·7H₂O stress by using real-time PCR analysis. The results indicated that the expressions of mpsA,thy,magA and mamB were related to Fe²⁺, and according to the fact that the strain ATCC 23270 only cultured in FeSO₄ could be able to synthesize intracellular magnetosomes, we supposed that these genes were related with the magnetosome formation in Acidithiobacillus ferrooxidans.In former study of the relation between magnetosome formation and Fe²⁺ by using the semisolid-plate magnetophoresis and TEM method. The strain ATCC 23270 cultured in FeSO₄ appeared in thin section to contain several electron-dense particles, correspondingly, the iron starvation control of strain ATCC 23270 lack these bacterial inclusion bodies. The isolated cells are able to orient and migrate to the magnet in artificial magnetic field but could not orient swimming only under the geomagnetic field. Meanwhile, we did further study on magA gene by bioinformation. This study analyzied the conserved domain and amino acid sequences as well as protein homologs. According to our bioinformatics results we supposed that ORF1124 was related to the formation of magnetosomes in Acidithiobacillus ferrooxidans and the formation mechanism of magnetosomes in Acidithiobacillus ferrooxidans might be different from that in magnetotactic bacteria. Moreover, we used BDGP website to search for potential upstream promoters of genes.