05/06/2011
Wood Degrading Fungi Use Specialized Systems for Degrading Different Plant Types
Summary
“Brown rot” and “white rot” fungi from forest floors are among the few organisms on Earth that can fully degrade both the long, repeated sugar chains (cellulose and hemicellulose) and the complex, interlinked network of aromatic compounds (lignin) that make up woody plant material. The two classes of fungi use distinct (but poorly understood) enzyme systems to break down biomass and show strong preferences for particular types of wood. A collaborative team of researchers at the DOE Great Lakes Bioenergy Research Center and the DOE Joint Genome Institute have examined representative species of brown and white fungi to determine which specific genes involved in biomass deconstruction are deployed to attack aspen or pine wood. These studies revealed that the two types of fungi used distinct deconstruction systems, and the expression of these systems was heavily influenced by the type of wood being degraded. Many genes identified in the study correspond to known biomass degradation enzymes, but a significant fraction have no currently known catalytic function and will be the subject of further investigation. The results of this study increase our understanding of molecular mechanisms that allow degradation of biomass and could lead to the identification of new systems for plant deconstruction and biofuels production.
References
Wymelenberg, A. V., et al. 2011 “Significant Alteration of Gene Expression in Wood Decay Fungi Postia placenta and Phanerochaete chrysosporium by Plant Species,” Applied and Environmental Microbiology, DOI:10.1128/AEM.00508-11.