Microorganism-Mediated Sequestration of Ferric and Ferrous Ion from the Environment

As an abundant and versatile element, iron plays an important role in industry and in many ecological systems. Microorganisms are dependent upon iron for electron transport and as the cofactor in numerous enzymes. The sequestration of ferric ion (Fe³⁺) poses a challenge to microorganisms due to its low solubility in aerobic conditions. Varied systems allow microorganisms to acquire and store iron. Microbes thus invoke mechanisms such as siderophores, heme use, transferrin, lactoferrin, and ferrous ion in order to sequester iron from the environment. This chapter discusses the ways by which microbes sequester, transport, and gain the iron from these sources by both Gram-positive and Gram-negative bacterial species.