from R. Martin Roop II, Eric Anderson, Jenifer Ojeda, David Martinson, Evan Menscher and Daniel W. Martin writing in Brucella: Molecular Microbiology and Genomics:
Like most other living organisms, Brucella strains require a variety of metals as micronutrients to serve as co-factors and structural components of enzymes and other cellular proteins. Genetic studies have shown that the efficient transport of iron, magnesium, manganese, and zinc are essential for the virulence of Brucella strains in experimental and natural hosts. This chapter will review what is presently known about the metal acquisition and homeostasis systems in Brucella strains.
Further reading: Brucella: Molecular Microbiology and Genomics