Phylogeny and Comparative Genomics Of Thermophilic Fungi

The ability to thrive at high temperatures is rare among eukaryotes. So far, fewer than 50 fungal species are regarded as thermophiles. Yet they have received considerable attention in the search of thermostable enzymes and thermophilic platform organisms for industrial applications. We have used the amino acid sequences of single copy house-keeping genes as phylogenetic markers to analyze the species phylogeny of the thermophilic fungi. The majority of the thermophilic fungi belong to the orders Sordariales and Eurotiales, three species belong to the Mucorales and one to Onygenales. The thermophiles within the Sordariales and Eurotiales are polyphyletic, suggesting that thermophily has arisen multiple times in these orders. We have sequenced the genomes of ~30 fungal thermophiles and examined their ability to degrade lignocellulosic biomass using transcriptomic and exo-proteomic approaches. The Sordariales thermophiles have over 200 genes each in encoding biomass-degrading enzymes while the thermophiles from the Mucorales possess far fewer genes for biomass degradation. Moreover the sets of enzymes deployed by these fungi in the decomposition of monocot straws are different from those used to breakdown dicot straws.