Using the excess beetle-killed pine as a source of fermentable sugars, the researchers used genomics to determine the most efficient methods to liberate fermentable sugars from the pine. In order to produce ethanol from the complex sugars in woods such as lodgepole pine, the wood from trees must be pretreated using a variety of different methods and then enzymatically digested into fermentable sugars. One method to liberate fermentable sugars is using fungi that can digest the complex lignocellulose sugar in the wood. The researchers identified proteins that improve the enzymatic hydrolysis of specific lignocellulosic feedstocks by analyzing the proteome of secreted proteins (enzymes) in wood-degrading fungi. New hydrolytic and non-hydrolytic proteins with enhanced-activity towards pretreated biomass were identified and used to develop improved enzyme cocktails for conversion of biomass to fermentable sugars. Although these newly developed enzymes mixtures showed enhanced robustness compared to commercial enzyme mixtures, the addition of auxiliary enzymes to these new cocktails could further reduce enzyme loading and increase the hydrolytic enzyme mixture’s robustness, decreasing the need for high severity conditions and ethanol fermentation inhibitors.
Scenario analyses, determined that the minimum ethanol selling price (MESP) of lignocellulosic ethanol produced from Canadian forest biomass is $0.80-1.10L, with most scenarios in the $0.90-0.95L range, compared with recent corn and sugarcane ethanol MESP of $0.30-0.40L.