Brown rot fungi Gloeophyllum trabeum and Postia placenta were used to degrade aspen, spruce, or corn stover over 16. weeks. Decayed residues were saccharified using commercial cellulases or brown rot fungal extracts, loaded at equal but low endoglucanase titers. Saccharification was then repeated for high-yield samples using full strength commercial cellulases. Overall, brown rot pretreatments enhanced yields up to threefold when using either cellulase preparation. In the best case, aspen degraded 2. weeks by G. trabeum yielded 72% glucose-from-cellulose, a 51% yield relative to original glucan. A follow-up trial with more frequent harvests showed similar patterns and demonstrated interplay between tissue modifications and saccharification. Hemicellulose and vanillic acid (G6) or vanillin (G4) lignin residues were good predictors of saccharification potential, the latter notable given lignin's potential active role in brown rot. Results show basic relationships over a brown rot time course and lend targets for controlling an applied bioconversion process.
Bibliographical noteFunding Information:
We are grateful for funding through a U.S. Department of Energy (DOE) Biomass Initiative Grant, number GO18088 . We also acknowledge the input of Dr. Charles Abbas from Archer Daniel Midland (ADM) Corporation, Mr. Jake Tewalt of POET, and Mr. Justin Kaffenberger of the University of Minnesota.
- White rot