Biodegradation of wood treated with copper based preservative by two dematiaceous fungi: Alternaria Tenuissima and Ulocladium Consortiale

Abstract

As cases of treated wood colonization by fungi still happen, the understanding of fungal survival abilities could contribute in the creation of new efficient preservatives. For that reason, two dematiaceous fungi Alternaria tenuissima and Ulocladium consortiale isolated from treated wooden joists with discolorations were tested for their wood decomposition ability and tolerance to a copper based preservative. Our results indicated that the copper based preservative failed to suppress completely cellulose and lignin biodegradation by discoloring fungi studied in wood. Moreover, cellulose degradation was higher in the treated sawdust for both fungi after 30 days than in the untreated. Comparing the results of two strains U. consortiale that is little studied as a wood decomposer, was stronger lignin degrader than A. tenuissima in treated and untreated sawdust. The copper sulphate tolerance test showed that both fungi were able to grow up to 7 mM concentration in a solid medium.