Lignocellulosic material is both the most abundant source of biomass on the planet and an enormous storehouse of sugars. Yet the sugars in cellulosic material are remarkably recalcitrant. The ability to detect new enzymes, to produce them in large quantities, and to understand how they work will lay the groundwork for the development of more efficient and economical processes for lignocellulosic biomass. We are particularly interested in harnessing the ligocellulolytyic ability of thermophilic fungi as they are potential reservoirs of thermostable enzymes for industrial applications. So far, fewer than 50 fungal species have been described as thermophiles. We have sequenced over 20 species of thermophilic fungi, see www.fungalgenomics.ca. Most of these thermophiles belong to the orders Sordariales and Eurotiales, three species belong to the Mucorales and one to Onygenales. We have developed computational tools to improve the identification genes in fungal genomes in general, and genes encoding extracellular proteins in particular because biomass-degrading enzymes are predominantly extracellular proteins. In addition to using informatics tools to identify orthologues of lignocellulolytic enzymes, we have analyzed the transcriptomes and exo-proteomes of the thermophilic fungi when cultured in a variety of agricultural straws to reveal the strategies used by different fungi in the decomposition of lignocellulose as well as identifying novel extracellular proteins that may play a role in biomass decomposition. Over 2000 genes encoding potential lignocellulolytic proteins have been identified. The Sordariales possess a larger repertoire of lignocellulolytic enzymes than the thermophiles from other orders. The genes predicted to encode lignocellulolytic proteins have been cloned and transformed into Aspergillus niger for the production of recombinant enzymes. Biochemical characterization of the recombinant enzymes show that in addition to producing enzymes that are thermostable, the thermophiles also produce enzymes that have temperature optimum in the 40-50Â°C range.
Full conference title:
27th Fungal Genetics Conference
- FGC 27th (2013)