Production and isolation of siderophores from the soil fungus Epicoccum purpurascens

Abstract

A large number of iron transport agents, siderophores, which stimulated the growth of Arthrobacter flavescens JG-9, were isolated during a study of the antitumor activity associated with the metabolic products of the fungus Epicoccum purpurascens. The production of the siderophores was significantly enhanced in a variety of media by culture of the fungus in the near absence of ferric iron. A novel method of purification involving a carboxylic ion-exchange resin separated the siderophores into four subgroups. The first subgroup, which contained the majority of the activity, was subsequently resolved in a similar manner with the carboxylic resin into seven individual siderophores. Of these, two were characterized as ferricrocin and coprogen whereas the others appeared to represent new compounds. One of the latter was given the name triornicin and exhibited slight antitumor activity in mice injected with Ehrlich ascites tumor cells.

Root-microbial effects on plant iron uptake from siderophores and phytosiderophores

“…contaminated with seed mieroflora and microorganisms introduced by routine handling), with similar plants that were additionally inoculated with a soil suspension (garden soil, Universitfit Hohenheim) or a root-colonizing bacterium, Arthrobacter flavescens JG-9 (Aureobacterium flavescens, ATCC 13348). The latter bacterial inoculum was produced as a 48-hr culture in Arthrobacter assay medium (Frederick et al, 1981) agitated at 100 rpm on a rotary shaker at 27°C, and was added at a rate of 5 ml per 3-L container 3 days prior to the uptake experiment. Other plants were inoculated with 5 mL of a mixed soil inoculum obtained from a soil:water (2:1) suspension filtrate passed through Whatman no.…”

NBRI16716A, a new antitumor compound against human prostate cancer cells, produced by Perisporiopsis melioloides Mer-f16716

“…9,11 It is interesting that 3 unexpectedly could not exert differential growth inhibitory activity similar to 1 and 2 (Figure 3), suggesting that N-hydroxyamide moiety at N-16 might be critical to the activity. Although the mechanisms of actions of 1 and 2 as well as that of triornicin are still unknown, they might have a similar target.…”

“…The characteristic color reaction to FeCl 3 indicated that they were a family of siderophore. 9 The molecular formulae of 1, 2 and 3 were determined to be C 18 …”

Solubilization of cobalt from ocean nodules at neutral pH?a novel bioprocess

“…Sequestration of iron is often achieved by siderophores, a class of microbially produced organic ligands having conditional stability constants in the order of 10 19 -10 22 M )1 . Most siderophores are of two types, catecholate and hydroxamate [3,6,14,15,17,22,25,26,27,29]. …”