The formula to low-cost biofuel might be found within mushrooms. A team of scientists including researchers from the Energy Department’s Joint Genome Institute identified Thielavia terrestris and Myceliophthora thermophilia — two types of fungi that thrive in the hot environments necessary to speed up the biofuel refining process, according to a Nature Biotechnology article published this week (subscription required).
Why it matters
The federal government has mandated that 36 billion gallons of renewable fuel be blended into transportation fuel by 2022. While corn-based ethanol production has increased, the development of so-called next-gen biofuels made from non-food crops (or cellulosic ethanol) has fallen flat. The mandate calls for 350 million total gallons of cellulosic ethanol to be produced by the end of this year. To date, zero gallons of qualifying cellulosic ethanol has been produced, according to R-squared blogger Robert Rapier.
Next-gen biofuels have struggled in part because the process of breaking down plant biomass and converting it into fermentable sugars so it can be refined into fuel is too expensive to be commercially viable. In other words, it can’t compete against corn-based ethanol prices or gasoline, for that matter.
Enter the heat-loving fungi. The Energy Department has several research projects aimed at finding heat tolerant enzymes from fungi and microbes such as cellulases that break down plant cell walls and convert biomass into fermentable sugars.
Heat tolerance is the critical cost-reduction piece of the puzzle. Many cellulases used in biofuel production thrive at temperatures of 20 degrees Celsius to 35 degrees C, according to the DOE’s Joint Genome Institute. (That’s between 68 degrees to 95 degrees Fahrenheit.) The conversion process at these temperatures take time, during which contaminants can reduce the final yield — and that means higher costs.
Researchers concluded the refining process could be sped up by raising the temperature. That means finding enzymes that can survive the heat. Now that the team of scientists has identified two heat-loving fungi, the information can be used to improve strains as well as simplify the indentification of other beneficial and harmful mutations, according to the DOE’s Joint Genome Institute.
The upshot? A faster, more efficient refining process that will help push costs down — and hopefully help it reach the much-sought after commercially viable zone.
Photo: Adrian Tsang, Concordia University via Energy Department’s Joint Genome Institute
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