The biomineralisation of magnetite (Fe 3O 4) requires regulating mechanisms to control the concentration of iron, the crystal nucleation, the redox potential and the acidity (pH). This is achieved by means of compartmentalisation in structures known as magnetosomes that allow the biochemical control of the above-mentioned processes. After the genome of several MTB species had been sequenced, a comparative analysis of the proteins involved in the formation of the BMP became possible.