ADHESION OF BLASTOSPORES OF SCLEROPHOMA-PITYOPHILA TO WATER-BORNE PAINTS IS MEDIATED BY SOLUBLE EXTRACELLULAR COMPOUNDS RELEASED DURING EARLY STAGES OF GERMINATION

Adhesion of blastospores of Sclerophoma pityophila (Corda) V. Honkel t o different wood paints was studied in relation to stage of germinatio n, It was found that adhesion to water-borne paints of different compo sition varied to a high extent. The highest number of blastospores adh ered to an acrylic paint containing a cellulose extender. The number o f blastospores that adhered to paint films on wood differed from the n umber of blastospores that adhered to free paint films of the same pai nts. Under the experimental conditions used, blastospores in freshly m ade spore suspensions did not adhere to paint films on wood. Maximum a dhesion of blastospores occurred when the spores were preincubated for between 150 and 210 minutes. With longer preincubation times the adhe sion of blastospores decreased drastically. By applying a concentratio n series of pullulan, a polysaccharide known to be produced by the blu e stain fungus Aureobasidium pullulans, it was shown that this polysac charide could promote adhesion of ungerminated blastospores of S. pity ophila to a paint film in concentrations of 0.16 mg l(-1) or higher. I t was also shown, by exchanging supernatants and blastospores from spo re suspensions preincubated for different time periods, that adhesion of newly harvested blastospores was improved by soluble extracellular compounds, probably polysaccharides similar to pullulan, released from germinating blastospores of S. pityophila.