Abstract Detail

Poster Session

Presley, Gerald  [1], Schilling, Jonathan S. [1].

Probing the Postia placenta secretome in early stages of wood decay.

Wood decay fungi are the principle agents of decay of recalcitrant woody biomass and utilize not yet fully understood biochemical mechanisms to derive a carbon source from wood. Brown rot fungi in particular are thought to generate extracellular hydroxyl radicals using Fenton chemistry to depolymerize wood polysaccharides within the S2 layer of wood cell walls while leaving lignin largely in-tact. During the course of decay hemicelluloses are removed from wood most rapidly, followed by cellulose, suggesting that there is a difference in the decay strategy employed by brown rot fungi in early stages of decay. We have developed a model system using wood wafers degraded by the brown rot model fungus Postia placenta that coax directional growth of wood decay fungi on the substrate. Thin sectioning and analysis of the fungal secretome has shown that the primary endoglucanase expressed by Postia placenta is not secreted in the earliest stages of decay (2-3 days post colonization) but becomes a major component of the extracellular protein fraction shortly thereafter and for the remainder of the decay process. Previous work has shown that wood polysaccharides are depolymerized in the early stages of wood decay were the endoglucanase is not detectable, which suggests that the brown rot fungi do not rely on cellulases to degrade wood polysaccharides in early stages of decay. This model system is being employed for further investigation of the brown rot secretome in incipient stages of decay in Postia placenta and other distantly related brown rot fungi.

1 - University of Minnesota, Bioproducts and Biosystems Engineering, 2004 Folwell ave, St. Paul, MN, 55108, USA

Keywords:
Brown rot
cellulase
Secretome.

Presentation Type: Offered Paper - Poster
Session: P4
Location: Lincoln Room/Kellogg Hotel and Conference Center
Date: Tuesday, June 10th, 2014
Time: 8:00 PM
Number: P4002
Abstract ID:125
Candidate for Awards:Graduate Student Poster Presentation Award