Research Highlights

The complex carbon-rich plant structure lignin can be broken down to make aviation fuel, plastics, and other commercial products. During chemical deconstruction of lignocellulosic biomass, the presence of phenolic pendant groups such as p-coumarate can improve the efficiency of deconstruction or lead to toxins that inhibit microbial fermentation of plant sugars. Though previously thought only to be in commelinid monocots, the list of pCA-containing eudicots is growing.

This work reviews the current landscape of plant genetics through the lens of bioenergy crops to present a roadmap for using DNA-based tools to engineer improvements.

Bioenergy sorghum is a drought-tolerant grass adapted low-productivity lands that promotes soil carbon stocks. An extended vegetative growth phase and long growing season produce 4-5 meter stems that account for about 80% of shoot biomass. During a typical growing season stem density increases significantly following stem internode growth. This study offers new insights on what causes it. 

This research enhances the selection and validation of upstream processing methods for lignocellulosic biomass pipeline processing, which improves economic and environmental outcomes for biorefineries, and shows the first comparison of pretreatment technique viability for oilcane.

Grasses and some tree species have naturally γ-acylated lignins. Poplar lignins have para-hydroxybenzoate groups on 1-15% of syringyl subunits. During hydrogenolysis, it is generally assumed that p-hydroxybenzoate is cleaved before the deacylated lignin is depolymerized. Here, scientists showed how the presence of a γ-acylated group alters the product portfolio produced by hydrogenolysis with palladium on carbon (Pd/C) as the catalyst.

Researchers characterized variation in ROS resistance across the ancient subphylum Saccharomycotina and used machine learning to identify gene families whose sizes were predictive of ROS resistance. The most predictive features were enriched in gene families related to cell wall organization and included two reductase gene families.

Switchgrass grown during drought conditions has high levels of osmoprotectant sugars and saponins that inhibit microbial conversion to biofuels. This experiment explored whether the inhibitory effect was specific to ammonia fiber expansion (AFEX) pretreatment and whether it could be alleviated by raising the pH of the hydrolysate.

Great Lakes Bioenergy Research Center scientists developed a mixed-integer quadratically constrained program to optimize the layout of a field-scale cropland considering economic, biodiversity, greenhouse gas emissions, and water quality objectives. Decision variables include spatially varying fertilization in addition to crop establishment location. The model also accounts for biodiversity effects of core area and edges between crops.

Soil organic matter is critical for soil health and resilience, yet conventional cropping systems in the U.S. Midwest have lost 40-60% of initial levels. This study underscores the importance of cover crops, perennial crops, and no-till options for sequestering whole profile C in intensively farmed croplands whether managed for cellulosic bioenergy or grain.

Bioenergy with carbon capture and storage (BECCS) may be necessary to limit the rise in global temperatures but requires vast amounts of land, and the change in land use could have positive or negative impacts on the climate. This work examines three methods for estimating the impacts and shows how some scenarios can reduce warming.