Palo Podrido: Model for Extensive Delignification of Wood by Ganoderma applanatum
AUTOR(ES)
Dill, Ingrid
RESUMO
Chemical and micromorphological analysis revealed that South Chilean “palo podrido” results from a white-rot fungus that causes highly selective and extensive delignification. Palo podrido samples from 10 different hardwood trunks (Eucryphia cordifolia, Drimys winteri, and Nothofagus dombeyi) decayed by Ganoderma applanatum were analyzed. Of 14 samples, 11 had extremely low Klason lignin values, ranging from 6.1 to 0.4% (dry weight). The most remarkable and unusual feature was that delignification and defibration were not restricted to small pockets but extended throughout large areas in the interior of trunks subjected to undisturbed rotting over long periods of time. Comparative analysis of water content, swelling capacity, and lignin content led to the conclusion that besides lignin degradation, suppression of the cellulolytic activity of the rotting organisms plays a decisive role. Among various nutrients added to a palo podrido sample (3% residual Klason lignin), the nitrogen source was the only one leading to almost complete cellulose degradation. We suggest that the extremely low nitrogen content (0.037 to 0.073% [dry weight]) of the investigated wood species was the primary cause for the extensive delignification as well as the concomitant suppression of cellulose breakdown. The low temperatures, high humidity, and microaerobic conditions maintained within the decaying trunks are discussed as additional ecological factors favoring delignification in South Chilean rain forests.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=239226Documentos Relacionados
- Characterization of Palo Podrido, a Natural Process of Delignification in Wood †
- Resistance of TiO2-treated Eucalyptus botryoides Wood to the Fungus Ganoderma applanatum
- Comparative Studies of Delignification Caused by Ganoderma Species †
- Ultrastructural Aspects of Wood Delignification by Phlebia (Merulius) tremellosus†
- Selective Delignification of Aspen Wood Blocks In Vitro by Three White Rot Basidiomycetes †