Biogenic oxides from neutrophilic iron bacteria and possibilities for application in the nanotechnology

The aim of this study is to obtain and characterize the ferric oxides/(oxy)hydroxides formed after cultivation of bacteria under laboratory conditions. The pure cultures of these bacteria isolated from natural habitats are identified by the methods of classical and molecular taxonomy as strains of the Leptothrix genus. Adler (AM) and Silicon iron glucose peptone (SIGP) media are the most appropriate ones for obtaining the iron oxides. The characterization of the oxides and sheaths is performed by different physical methods. The sheaths are formed in a SIGP medium. Light micrograph images and SEM revealed the average size and diameter of the sheaths. The XRD measurements showed the composition of the oxides obtained, as well as the average size of the iron particles (up to 30 nm). The TEM micrographs showed the shape of the biogenic nanoparticles, while the magnetic measurements demonstrated the superparamagnetic character of the magnetic part of the biomaterials. The new biogenic materials are promising for application in magneto electronic for building biosensors.