A group of researchers has recently decoded the genomes of two heat-loving fungi, and that work may give a boost to sustainable fuel research. The team, headed up by investigators at Concordia University in Montreal, Quebec, mapped the genetic makeup of Myceliophthora thermophila and Thielavia terrestris, two fungi commonly found in compost that can self-ignite without a spark or accelerant. The group published their findings in Nature Biotechnology last month, in which it describes how the two thermophilic eukaryotes could also breakdown fibrous materials from plants at temperatures too hot for enzymes typically used in industrial processes for degrading biomass into chemicals and other products.
"In general, food precursors of biofuel such as corn or sugarcane are relatively easily and effectively broken down by existing commercial fungal and bacterial enzymes. But non-food biomass such as agricultural waste and forestry residues are really complex stuff that requires cocktails of enzymes to release the sugars they contain effectively, and convert the non-sugar portion to something that could be useful," says Justin Powlowski, as associate professor at Concordia and a co-author on the study. "The commercial enzymes that we now have do a reasonable job of converting lignocellulosic biomass into its components, but they are expensive. And in order for ligno-cellulosic biofuels or chemicals to be competitive with fossil-fuel based products, more efficient enzymes are needed."
The Broad Institute had previously sequenced the genome of Chaetomium globosum, a mesophilic relative of the two recently sequenced species, which Powlowski and his team thought provided an excellent opportunity to compare genomes across the three species. But as it turned out, it was difficult to find anything obviously different between the thermophiles and the non-thermophile, other than that Chaetomium often seemed to have more of everything. "Although we did manage to come to some conclusion relating to thermophily that are reported in the paper, the question of what equips these fungi to thrive at high temperature is largely unanswered," Powloski says. "Nonetheless, having the genomes sequenced really opens up the possibility for further experimentation to determine this."