Program Book - 27th Fungal Genetics Conference

PLENARY SESSION ABSTRACTSCarbohydrate-active enzymes in fungal genomes. Bernard Henrissat. AFMB, CNRS and Aix-Marseille University, Marseille, France.We term carbohydrate-active enzymes (CAZymes) the enzymes that assemble and breakdown complex carbohydrates and carbohydrate polymers. Assuch carbohydrates are crucial for fungi as carbon sources but also for cell wall synthesis/remodelling, host pathogen interactions, energy storage etc.Unlike many other classes of enzymes which carry limited informative power, the peculiarities of CAZymes and of their substrates turn these enzymes intoextremely powerful probes to examine genomes and explain the lifestyle of living organisms and fungi in particular. Over the last few years we haveexplored the CAZyme content of over 200 fungal genomes and we will review how evolution shapes the CAZyme profiles of fungi.Suggested reading :- Cantarel et al. (2009) The Carbohydrate-Active EnZymes database (CAZy): an expert resource for Glycogenomics. Nucleic Acids Res. 37: D233-D238- Ohm et al. (2012) Diverse lifestyles and strategies of plant pathogenesis encoded in the genomes of eighteen Dothideomycetes fungi. PLoS Pathogens,8(12): e1003037.- O’Connell et al.(2012) Life-style transitions in plant pathogenic Colletotrichum fungi defined by genome and transcriptome analyses. Nature Genetics44, 1060-1065- Floudas et al. (2012) The Paleozoic origin of white rot wood decay reconstructed using 31 fungal genomes. Science, 336, 1715-1719- Ma et al. (2010) Comparative genomics reveals mobile pathogenicity chromosomes in Fusarium oxysporum. Nature 464, 367-373- Martin et al. (2010) Périgord black truffle genome uncovers evolutionary origins and mechanisms of symbiosis. Nature 464, 1033-1038.Genome-wide approaches to identify and characterize lignocellulolytic enzymes. Adrian Tsang. Biol, Concordia Univ, Montreal, Canada.Lignocellulosic material is both the most abundant source of biomass on the planet and an enormous storehouse of sugars. Yet the sugars in cellulosicmaterial are remarkably recalcitrant. The ability to detect new enzymes, to produce them in large quantities, and to understand how they work will lay thegroundwork for the development of more efficient and economical processes for lignocellulosic biomass. We are particularly interested in harnessing theligocellulolytyic ability of thermophilic fungi as they are potential reservoirs of thermostable enzymes for industrial applications. So far, fewer than 50fungal species have been described as thermophiles. We have sequenced over 20 species of thermophilic fungi, see www.fungalgenomics.ca. Most ofthese thermophiles belong to the orders Sordariales and Eurotiales, three species belong to the Mucorales and one to Onygenales. We have developedcomputational tools to improve the identification genes in fungal genomes in general, and genes encoding extracellular proteins in particular becausebiomass-degrading enzymes are predominantly extracellular proteins. In addition to using informatics tools to identify orthologues of lignocellulolyticenzymes, we have analyzed the transcriptomes and exo-proteomes of the thermophilic fungi when cultured in a variety of agricultural straws to reveal thestrategies used by different fungi in the decomposition of lignocellulose as well as identifying novel extracellular proteins that may play a role in biomassdecomposition. Over 2000 genes encoding potential lignocellulolytic proteins have been identified. The Sordariales possess a larger repertoire oflignocellulolytic enzymes than the thermophiles from other orders. The genes predicted to encode lignocellulolytic proteins have been cloned andtransformed into Aspergillus niger for the production of recombinant enzymes. Biochemical characterization of the recombinant enzymes show that inaddition to producing enzymes that are thermostable, the thermophiles also produce enzymes that have temperature optimum in the 40-50°C range.22