Accumulation of the material containing the toxin cerato-ulmin on the hyphal surface of Ceratocystis ulmi

Abstract

Recovery of cerato-ulmin (CU) in the water extract from intact hyphae of Ceratocystis ulmi proved that it is present on the hyphal surface. Degrees of the accumulation of unidentified material on the cell surface of hyphae, together with CU recovery, varied from high, among isolates classified as distinct in CU production, to unmeasurable, among isolates classified as negligible in CU production. There was a correlation between the accumulation of unidentified material on the hyphal surface as observed under the scanning electron microscope (SEM) and recovery of CU from hyphal colonies. Most of the accumulated material was water-extractable, as is CU, and it is therefore concluded that the material accumulated on the hyphae of isolates classified as distinct in CU production does, indeed, contain CU.