The US Department of Energy launched three Bioenergy Research Centers just over ten years ago (earlier post). Of them, the Great Lakes Bioenergy Research Center (GLBRC), led by the University of Wisconsin–Madison, had a goal of turning more of the corn plant—the stalk and leaves that makes up the stover—into ethanol, while developing perennial plants like switchgrass and miscanthus (also called silvergrass) into potential feedstocks.
Now, GLBRC is taking its mission further. Instead of producing ethanol, GLBRC’s goal is now centered on designing advanced biofuels, such as isobutanol. These drop-in fuels could be used to replace gasoline without engine modification. By engineering bioenergy crops to enhance their environmental and economic value, and conducting research to generate multiple products from plant biomass, these advancements could optimize the bioenergy field-to-product pipeline.
Breaking down the more complex biological components of woody biomass to extract the sugars for fermentation into fuel is one step of the process. James Dumesic, a GLBRC researcher and UW–Madison professor of chemical and biological engineering, found a way to do just that with γ valerolactone (GVL), a chemical derived from plants themselves.
|GLBRC is working to increase the efficiency of biomass conversion. These bioreactors, located in UW–Madison’s Experimental Fermentation Lab, help researchers explore new ways of improving biomass fermentation. Source: GLBRC. Click to enlarge.|
Among the topics under research are:
Improving methods for feedstock-agnostic biomass deconstruction and separation by the renewable solvent γ-valerolactone (GVL) and broad-specificity glycosyl hydrolases (GHs).
Identifying metabolic burdens and lignocellulosic hydrolysate stresses and how they pose barriers to efficiently producing isobutanol (IBA).
Designing new platform microbes capable of producing targeted bioproducts from conversion residues created when producing specialty biofuels.
Devising feedstock-agnostic GVL- and GVL-enzyme methods that provide lignin and sugar for conversion to specialty biofuels and bioproducts.
Validating engineered biofuel microbes that can efficiently produce IBA or methylbutenol (MBO) in GVL-deconstructed lignocellulosic biomass from diverse bioenergy crops.
Engineering next-generation platform microbes that produce a range of high-value bioproducts from specialty biofuels conversion residue.
GLBRC scientists and engineers are also improving the yield and processing traits of dedicated bioenergy crops for cultivation on marginal, or non-agricultural, land. With smart management, these crops have the potential to benefit the ecosystem, help mitigate climate change, and provide farmers with an additional source of revenue.
GLBRC director and UW–Madison professor of bacteriology Tim Donohue’s specialty at GLBRC is in studying how microbes can digest these broken-down pieces of the plant to produce valuable products.
We’re trying to re-task native pathways and engineer next-generation microbial factories that can manufacture valuable fuels and chemicals from renewable wastes.—Tim Donohue
GLBRC is focused on enabling a new and different biorefinery, one that is both economically viable and environmentally sustainable. Realizing this goal will mean increasing the efficiency of biomass conversion and generating a mix of specialty biofuels and environmentally-friendly bioproducts, from as much of a plant’s biomass as possible.
One such discovery breaks down lignin’s six-carbon rings—the aromatics—into individual components. Traditionally sourced from petroleum, aromatics are used in a wide variety of products, including plastic soda bottles, Kevlar, pesticides, and pharmaceuticals, and are essential components of jet fuel.
We are in a unique position to not only address a major societal challenge, but to create new revenue sources and economic opportunities for farmers, rural communities and a new generation of bio-refineries.—Tim Donohue