Microbial ligand coordination: Consideration of biological significance

Siderophores are generally considered to be microbial chelating compounds secreted by bacteria to facilitate uptake of iron(III). Certain siderophores, however, have a high affinity for other transition metal ions, including manganese(III), copper(II), molybdenum(VI), and vanadium(V). A new class of microbial ligands produced by methanotrophs, called chalkophores, is produced to facility copper uptake. This review considers the coordination of siderophores to Mn(III), Cu(II/I), Mo(VI) and V(V), and their stability constants relative to Fe(III), when available, as well as the coordination complexes of chalkophores to Cu( l). (C) 2015 Elsevier B.V. All rights reserved.