A promising avenue of research in materials science is to follow the strategies used by Mother Nature to fabricate ornate hierarchical structures as exemplified by organisms such as diatoms, sponges and magnetotactic bacteria. Some of the strategies used in the biological world to create functional inorganic materials may well have practical implications in the world of nanomaterials. The aim of our work is to examine the synthetic of magnetite nanoparticles under different conditions to show the influence in magnetic properties of magnetite nanoparticles. Magnetospirillum strain AMB-1 was used in this study in order to produce magnetite nanoparticles. Magnetite nanoparticles of average size~47 nm were obtained. The magnetic properties of magnetite nanoparticles under different incubation temperature were examined and a small influence in magnetic properties of magnetite nanoparticles was indicated.