Authors: V. Morillo, M. Márquez, A. Morales
Affilation: Universidad Nacional de Colombia Sede Medellín, Colombia
Pages: 409 - 413
Keywords: magnetotactic bacteria, biogenic magnetite, magnetosome, single domain
Intracellular biogenic crystals synthesized by freshwater magnetotactic bacteria (MTBs) from Colombia were characterized. MTBs were separated from water/sediment samples using a magnetic field of 6 Gauss. Bacteria were observed by transmission electronic microscopy (TEM). Bacterial concentrated were analyzed with X-ray microdiffraction, Fourier Transform Infrared spectroscopy (FTIR) and magnetic measurements. Magnetosomes were measured and analyzed with EDX/TEM (Energy dispersive X-ray spectroscopy/Transmision Electron Microscopy). Results showed magnetite crystals with cuboctaedral, hexagonal prismatic morphology and bullet morphology; most of crystals were classificated in the single domain magnetic state, with an average length < 100 nm. Samples with MTBs were saturated in a field near to 100 mT, showing ferrimagnetic minerals. This Results open path to others studies with MTBs in Colombia, allowing to find applications of magnetic biominerals in nanotechnology and biomedicine.