Studies on the Metabolic Function of the Ferrichrome Compounds

Abstract

Ferrichrome is a representative member of a group of microbial products which show very intense growth factor activity when tested with a small number of selected fungal and bacterial species (1).Some of the members of this group of compounds, e.g.aspergillic acid (2), nocardamin(3), and grisein (albomycin) (4), are potent antibiotics against certain strains of microorganisms.Although the ultimate physiological function of the ferrichrome compounds is unknown, there is considerable evidence that would implicate them as catalysts for the transport and metabolism of iron.The available information relevant to this point of view has been discussed elsewhere (1).In the present communication we wish to describe the natural distribution and some of the nutritional aspects of ferrichrome.In addition, results will be reported for certain studies on the physiology of a bacterial species which requires ferrichrome for growth.These experiments offer the first tangible evidence in support of the theory that ferrichrome functions as an irontransporting agent in microbial metabolism.EXPERIMENTAL PROCEDURE Materials and MethodsSeveral members of the genus Arthrobucter require ferrichrome, terregens factor, coprogen, or hemin as a growth factor (5).The microorganism used in this investigation was isolated from a soil sample by Greenberg and Barker' and has been tentatively classified by Starr2 as Arthrobucter JG-9.Throughout the present work, this organism has been used both for studying the distribution of ferrichrome activity and for examining the physiology of a ferrichrome-deficient cell.Since Arthrobacter JG-9 responds to both hemin and ferrichrome', cultures which were surveyed for the production of the latter factor were also checked for the presence of bound hydroxylamine.A generous supply of stock microbial cultures was furnished