DETECTION AND IDENTIFICATION OF FERRICROCIN PRODUCED BY ECTENDOMYCORRHIZAL FUNGI IN THE GENUS WILCOXINA

The ectendomycorrhizal fungi Wilcoxina mikolae isolates CSY-14 and RMD -947 and W. rehmii isolate CSY-85 were grown in pure culture under iro n-limiting conditions. All three isolates tested positive for sideroph ore formation using both the ferric perchlorate assay and a sensitive HPLC iron-binding assay. A peptide siderophore was isolated from the c ulture medium by HPLC and shown to contain the amino acids serine, gly cine and ornithine in a 1:2:3 ratio, This siderophore was identified a s ferricrocin on the basis of electrospray mass spectroscopy and its c o-chromatography in two different HPLC systems with ferricrocin isolat ed from Aspergillus fumigatus. Ferricrocin was the only siderophore is olated from these Wilcoxina cultures, This is the first report of side rophore formation by ectendomycorrhizal fungi.