Generating more than 1,000 publications in peer-reviewed journals, ORNL’s pioneering leadership of two Bioenergy Research Centers has encompassed numerous notable scientific achievements, early-stage technologies and commercial licenses for the development of advanced biofuels and bioproducts.
Established by the Biological and Environmental Research program in the U.S. Department of Energy’s Office of Science, the bioenergy research center at ORNL was launched in 2007 as the BioEnergy Science Center (BESC) with a 10-year mission targeting biomass recalcitrance, or the natural resistance of plants to release sugars for conversion to biofuels. Today, research continues under the Center for Bioenergy Innovation (CBI), building on this legacy of scientific understanding to provide breakthroughs for a new generation of cost-effective, environmentally positive, and industrially relevant bioproducts and biofuels. This scientific achievement represents the combined work of more than 300 scientists across 18 partners.
“BESC research redefined recalcitrance” said ORNL’s Brian Davison, chief scientist for CBI. “When the research team set out to address recalcitrance as a major economic barrier to biofuels production, we understood it as a single phenotype, or trait, of plants. We’ve transformed scientific understanding of recalcitrance and demonstrated that it’s a set of properties that can be manipulated.”
Researchers showed that manipulation of multiple genes can produce perennial plants that break down more easily to produce biofuels.
“Collaboration is a cornerstone of BESC and CBI’s success,” said Moe Khaleel, associate laboratory director for Energy and Environmental Sciences. “The research team leverages key capabilities at ORNL and partner institutions to generate scientific breakthroughs that address national energy challenges.”
In one key publication, researchers shared insights into nature’s best biocatalysts, the organisms used to digest and convert plant material into biofuels. Among the microbes evaluated, researchers discovered that Clostridium thermocellum (CT) was twice as effective as fungal enzymes used by industry today.
“We found that biological solutions like CT offered the most promise for combining the processes of cellulose digestion and fermentation of released sugars into a single step without the addition of costly enzymes,” Davison said. “We concentrated our efforts on this microbial path to efficient, low-cost processing.”
Researchers developed genetic tools for use with CT and other microbes and used these tools to engineer better microbes, identifying genes responsible for critical traits such as tolerance to ethanol and promoting those genes. The research, detailed in the Proceedings of the National Academy of Sciences, ultimately led to a microbe custom-designed to produce ethanol efficiently. Enchi licensed the technology in 2017 and is scaling it for use in biofuels production.
These advances in conversion were complemented by the identification and development of plant lines containing less lignin, a natural polymer that helps plants maintain structural rigidity and also inhibits the breakdown of plant matter for biofuels. Scientists showed that reducing lignin content and modifying lignin composition improved conversion. Identifying the genes responsible for lower lignin content in a species of poplar (Populus trichocarpa) was enabled by the largest-ever dataset of genetic variations in poplar trees.
Known as the Genome-Wide Association Study (GWAS), the dataset comprises more than 28 million single nucleotide polymorphisms, or genetic variations, derived from approximately 900 poplar genotypes. The data give scientists unprecedented statistical power to link DNA changes to physical traits.
Using GWAS, researchers identified a gene in poplar that makes it easier to convert poplar trees into biofuel. GreenWood Resources licensed the technology and plans to select and breed improved varieties of poplar with less lignin, providing easier access to the sugars that are converted into renewable fuels.
“The development of low-lignin poplar varieties is a great example of how basic energy research is informing real-world applications to enable a viable bioeconomy,” said CBI Director Jerry Tuskan. “Through CBI, we are custom engineering feedstock plants and microbes to create new sustainable bioproducts and drop-in biofuels made from non-food biomass.”
The foundational knowledge generated and shared through the first 1,000 scientific publications will accelerate innovation as CBI develops tailored plant materials and microbes that yield targeted products such as modified lignin for use in chemicals, polymers and materials.
The Center for Bioenergy Innovation is one of four Department of Energy Bioenergy Research Centers created in 2017 to expand on the foundational successes of former BRCs, to create advanced biofuels and bioproducts, and to lay the scientific groundwork for a new robust, biobased economy. Learn more at https://cbi.ornl.gov/.
ORNL is managed by UT-Battelle for DOE’s Office of Science. The Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, please visit http://energy.gov/science/.
