中国生物工程杂志

Acidithiobacillus ferrooxidans are able to synthesize intra-cellular electron-dense magnetite，which makes possible that we could obtain bio-nano-magnetic particles by cultivating Acidithiobacillus ferrooxidans. In order to isolate the strain which has the capacity to produce more magnetic particles, the solid-plate magnetophoresis method was firstly created. After isolation using the method, the rate of the cells which contain intra-cellular magnetic particles was increased from 30% to more than 90%, in addition, after isolation each cell possessed 2-5 magnetic particles which disperse in cells. 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. Magnetosomes produced by Acidithiobacillus ferrooxidans were range from 40nm to 90 nm according to the results of TEM. Energy dispersive X-ray analysis indicated that extracted magnetic particles consisted of oxygen and iron. The results show that some Acidithiobacillus ferrooxidans cells have weak magnetotaxis and they could be able to be separated by solid-plate magnetophoresis method from others. With the development of this new isolation method, it is possible that we could do deeper research to generate a comprehensive description of the mechanism that how Acidithiobacillus ferrooxidans synthesize the magnetic particles.