Inhibition of <i>Poria carbonica</i> by <i>Scytalidium</i> sp., an imperfect fungus isolated from Douglas-fir poles

Abstract

In a survey of the fungi in heartwood of Douglas-fir poles, three conditions were observed: no fungi, unifungal cultures of Poria carbonica Overh. or related basidiomycetes, and a mixed microbial population. From some apparently sound wood cores, a species of Scytalidium was isolated, usually as a unifungal culture. This organism was distinguished by release of a water-soluble yellow pigment into the agar and production of dark spores as the colony aged. Strong antagonism of Scytalidium sp. to P. carbonica on malt extract agar was attributed at least partly to the production of an antibiotic substance by Scytalidium. There was no evidence of change in the mechanical properties of the wood or of injury to the wood cells as a result of Scytalidium growth. The xylan moiety in the hemicellulose was the preferred energy source observed. Wood chips permeated with this organism and then steamed were not damaged by an actively growing colony of P. carbonica.