Great Lakes Bioenergy Research Center 2012 Science Report by Great Lakes Bioenergy Research Center

2012 Science Report

Our Mission

OUR COLLABORATIVE APPROACH

Our mission is grand, but simply stated: to perform the basic research that generates technology to convert cellulosic biomass to ethanol and other advanced biofuels.

Our Role In order to focus the most advanced biotechnology-based resources on the biological challenges of biofuel production, the U.S. Department of Energy (DOE) established three Bioenergy Research Centers (BRCs) in September 2007. The Great Lakes Bioenergy Research Center (GLBRC) is led by the University of Wisconsin-Madison (UW– Madison), with Michigan State University (MSU) as the major partner. Additional scientific partners are a DOE National Laboratory, other universities and a biotechnology company. GLBRC’s researcher expertise covers a wide array of disciplines, from microbiology to economics and engineering. Each Bioenergy Research Center is pursuing the basic research underlying a range of high-risk, high-return biological solutions for bioenergy applications. Advances resulting from the BRCs will provide the knowledge needed to develop new bio-based products, methods and tools for the emerging biofuels industry.

Our Members

Director Tim Donohue describes the disciplinary diversity characterizing GLBRC research, and explains why it is vital to the Center’s success.

TIM DONOHUE VIDEO

ASK AN EXPERT HOME

Great Lakes Bioenergy Research Center

What’s Next for Energy Research at UW-Madison?

f the energy and excitement of researchers and staff moving into the Wisconsin Energy Institute (WEI) building is any indication, I am confident that the coming year will be a time of rapid growth for energy research on campus. Situated next to the College of Agricultural and Life Sciences (CALS), the College of Engineering, and in close proximity to the College of Letters & Sciences and the Wisconsin Institutes for Discovery, the WEI is strategically placed within a new campus research corridor— one that is ideal for collaborative energy research and technology transfer to real-world energy applications.

The WEI building is state-of-the-art and promises to be part inspiration, part collaboration magnet. Within its walls, individual Michael Corradini labs are focused on growing Director, Wisconsin Energy Institute sustainable feedstocks, proWisconsin Distinguished Professor ducing next generation fuels Engineering Physics and harnessing renewable University of Wisconsin-Madison sources of energy as part of an integrated energy systems concept of energy storage and flexible delivery technologies. Though UW–Madison is already a prolific source of clean energy research and development, WEI is amplifying these efforts with its activities. As engineers, agronomists, biochemists and modeling experts set up shop to tackle a wide variety of questions surrounding our grand energy challenge, I am hopeful that new avenues of discovery and new collaborations will emerge. Kick-starting a new mode of collaboration for federally-funded basic research, the Great Lakes Bioenergy Research Center has been an excellent example of the success that is possible when a a diverse team is assembled around a central mission and given resources to innovate. During their first Department of Energy grant cycle, the Center contributed more than 400 research publications to the literature on bioenergy and generated nearly 60 patent applications — all while training a new generation of energy professionals to work in the lab, field, office and classroom. In 2012, UW-Madison leadership, led by the Provost and the Deans of CALS and Engineering, united campus energy research under one banner. By welcoming the Great Lakes Bioenergy Research Center as a member, the Wisconsin Energy Institute will continue to spur research collaborations in support of multidisciplinary energy discovery. We are thrilled to have such strong campus support for uniting life sciences researchers, physical sciences engineers and social sciences experts on energy. As we launch this new endeavor in support of research and technology development, we invite you to work with us. This grand challenge is larger than all of us, and we are eager to be part of a comprehensive approach to research, scholarly debate and public engagement on the issue of energy. We invite you to join us for our building grand opening on April 5th and 6th. With a student career fair, facility tours and technology demonstrations on the event docket, we hope to provide a little something for everyone.

WISCONSIN ENERGY INSTITUTE The WEI is creating, integrating and transferring knowledge in energy sources, technologies, use and impacts. Our efforts focus on making breakthroughs in key areas of the energy sector: • Feedstocks • Carbon neutral electricity • Liquid transportation fuels • Energy storage • Policy, economics and environment Innovations in these fields will strengthen and diversify approaches to generating, storing, distributing, and using energy while conserving valuable and increasingly limited resources. The integration of research, discovery, and technology transfer that is central to the WEI’s approach is expected to provide a robust suite of clean energy strategies.

ENERGY.WISC.EDU

Contents 4

Our Research Progress

Biomass-to-Products Pipeline

Platform Chemicals Create New Value Streams

Spinning Straw into Gold with Co-Products

Getting to Know Our Team: Four Conversations

Streamlining Process Design with Models

Accelerating Agriculture with Multi-Purpose Landscapes

Collaboration, Technology and Commercialization

Enriching Education

Find Us, Contact Us and Credits

2012 Science Report

Our Research Progress

Ken Keegstra Scientific Director Great Lakes Bioenergy Research Center

t the Great Lakes Bioenergy Research Center, we’ve spent five years pursuing a diverse set of approaches and utilizing a wide range of tools and expertise that will help us create new technologies for producing advanced biofuels. Rather than focus exclusively on one approach, our researchers are exploring multiple processes — ranging from oil extraction to both alkaline and acid pretreatment strategies — that can create new value streams for intermediates like specialty chemicals and end products like fuel.

As we’ve matured, we’ve increased our focus on areas that the biofuels industry categorizes as obstacles. When Great Lakes Bioenergy research sheds light on a widespread problem, we can have an impact on multiple points throughout the biofuels landscape. One obstacle for the biofuels industry is lignin, and we’ve made important advances that will reduce the energy needed to utilize this promising source of fuels and chemicals. By applying unique alkaline pretreatment strategies, we hope to harness a reliable lignin stream, which opens up tremendous possibilities for valuable co-products–materials that can add value to the biofuels pipeline (read more on page 8). From a biological perspective, we’re taking a close look at what stressors keep microbes from doing their jobs effectively. We know there are many sources of microbial stress, and going forward, we’ll continue to focus on them using genomic tools to gain insight into how to give microbes the ability to handle those stressors. At the landscape scale, GLBRC sustainability researchers have been concerned from the start about how to introduce bioenergy crops into the landscape without causing unintended environmental, economic or social consequences. One possible and promising solution is the use of marginal lands. Combining agronomic expertise with massive modeling power, our researchers have confirmed that enough marginal lands exist in the Midwest alone to provide annually 25 percent of the Energy Independence and Security Act requirement (read more on page 13). This year was filled with exciting progress in both basic and applied research. Over the summer we marked an important Center milestone: our first issued patent. In the fall, we celebrated the first license on a GLBRC technology. Using ionic liquids to break down cellulosic biomass into fermentable sugars, the technology will be developed by biotechnology startup Hyrax Energy, the first company to emerge from GLBRC research (read more on page 17). In this year’s report, we hope you’ll enjoy learning more about our scientific achievements, the people behind our research (see page 10), and our plans for the years ahead.

Products • Cellulosic biofuel: Renewable fuel that is derived from the nonfood parts of plant biomass, such as leaves and stalks. • Co-products: Useful compounds other than fuels generated during biofuel processes. May have important commercial applications that can add value to biofuel production and industry. • Drop-in fuel: Can be used within existing energy infrastructure with little additional modification or cost.

Processes • Fermentation: Process where microorganisms such as bacteria or yeast break down organic matter into simpler compounds. In the case of ethanol, yeast is used to ferment simple sugars, yielding both carbon dioxide and fuel. • Fermentation inhibitor: Formed during the breakdown of plant sugars, chemical inhibitors can hamper fermentation by interfering with the activity of fermentation microbes. Some inhibitors have value as platform chemicals (see page 6). • Hydrolysis: Chemical decomposition of a compound involving reaction with water. In many biomass deconstruction reactions, enzymes are used to catalyze hydrolysis. • Pretreatment: Process performed prior to biomass deconstruction and conversion to biofuel which may involve using a combination of heat and chemicals to break down plant material.

Building Blocks • Lignin: Irregular, branching organic polymer that makes up a third of all plant biomass, and lends rigidity and structure to plant tissues. • Platform chemicals: Form the chemical foundation for a variety of value-added compounds used in the manufacture of both industrial and everyday products and materials. • Monosaccharide, or simple sugar: Basic molecular unit of all carbohydrates. Examples include glucose, xylose, sucrose, lactose, and fructose. Food source for fermentation microbes. • Polysaccharide, or complex carbohydrate: Long chain of monosaccharide molecules. Cellulose, a glucose polysaccharide, is the most abundant organic compound on earth; it forms the structural basis of plant cell walls, and is the primary storage unit for sugars used in biofuel production.

Feedstocks • Biomass: In the context of biofuels, the agricultural residues, forestry materials, crops, vegetation, and other plant materials that can be converted to energy. • Biofuel feedstocks: Raw plant material used to produce cellulosic biomass, such as corn stover (the stalk and leaves of the corn plant), grasses and woody plants.

Great Lakes Bioenergy Research Center

Oils Fuels

Biological Conversion Fuels

Fuels

Speciality Chemicals

Fuels

Speciality Chemicals

Fuels

Speciality Chemicals

Platform Chemicals

Intermediates

Platform Chemicals

Fermentation

Lignin Conversion

Sugar Conversion

Lignin Conversion

Sugars

Oil Extraction

Chemical Conversion

Intermediates

Electric Power

Plastics

Sugars

Lignin

Pretreatment (Ammonia)

Plastics

Lignin

Solvent Addition

Cellulosic Biomass

As Great Lakes Bioenergy charges ahead into its sixth year of basic research, our scientists and engineers are focused on using each plant cell component, chemical intermediate and building block to help replace fossil fuels and other petroleum products while adding value to the biofuels production chain. The diagram above lays out the starting materials, intermediate components and variety of end uses for cellulosic biomass that are being explored within GLBRC labs. See the definitions (at left) for terms that are shown in the diagram or referenced throughout the report.

2012 Science Report

Platform Chemicals Create New Value Streams

UW-Madison Professor of Chemical and Biological Engineering James Dumesic (left) checks on an experiment with postdoctoral fellow Jeremy Luterbacher (right). Dumesic’s lab leads research on the catalytic conversion of cellulosic biomass to fuels and chemicals.

epending on the configuration, a Tinkertoy piece can either result in a connection or a dead end. In the realm of biofuels, these pieces take the form of chemical compounds like furfural and levulinic acid (LA), which can stifle or strengthen fuel production.

At the GLBRC, James Dumesic is working to leverage furfural and LA, which are known inhibitors of biomass fermentation to ethanol. Using a technique called heterogeneous catalysis, Dumesic and his team can turn these compounds into platform chemicals—molecular springboards for manufacturing useful products ranging from footwear to fuel. “Fermentation-wise, you don’t want the furfural and LA,” says Dumesic, a professor in the UW–Madison College of Engineering. “But we take these fermentation inhibitors and we try to make as much of them as we can. Then, we convert them to other [materials].” Platform chemicals form the basis of compounds found at home and in industry, including resins, paints, sporting equipment, detergents, cosmetics, and pharmaceuticals. Scientists can also use these compounds to generate fuels like gasoline and diesel. “The concept that we follow is to convert sugars first into platform molecules,”

says Dumesic. “On the other hand, if you want a fuel, then these platform molecules can be processed further into hydrocarbons.” Hydrocarbons derived from platform molecules can be readily ‘dropped in’ to the same fuel infrastructure currently used to power today’s busy world of travel and trade. Drop-in fuels produced by Dumesic’s team could be mixed with gasoline for the daily highway commute, while others are better suited for use in heavy transportation systems like airplanes. In addition to their versatility, these platform chemicals are also renewable because they are derived from plants. That means they could provide more sustainable alternatives to some petroleum-based materials as global fossil fuel supplies continue to dwindle. While the renewable properties of these platform chemicals can provide an environmental advantage, cost-effectiveness must be achieved before that advantage can be realized.

Great Lakes Bioenergy Research Center Zachary Ellis, a licensing associate with the Wisconsin Alumni Research Foundation (WARF), sees potential for the industrial application of biomass-derived chemicals and fuels. In a WARF-coordinated market analysis, Ellis found that furfural and LA have high market values. The key to industry, he says, now depends on developing processing reactions that hit a commercial sweet spot: they must produce fuels and intermediate chemicals on a large scale for a low cost that will appeal to manufacturers. “Professor Dumesic is a thought leader in the field of deriving chemicals from biomass—he has pretty much defined a lot of the intellectual property landscape himself,” says Ellis. “Now, the challenge is to produce large quantities of these chemicals at a competitive price.” For manufacturers, adopting biomass-derived chemicals and fuels means that the price of renewables must be low enough to make the transition affordable. The expenses associated with such a transition are referred to as ‘switching costs.’ “If you go from using an iPhone to using a Droid, assuming the phones are the same price, then the cost to switch might

include having to buy a new phone charger and new cases,” explains Ellis. “In order for Dumesic’s technologies to be attractive, he has to make his products a certain percentage cheaper to justify the switching costs.” Fortunately, because drop-in fuels by definition do not require a significant amount of new infrastructure, the switching costs associated with them are relatively low. Dumesic has been able to distill biofuels generated from catalytic reactions using an approach that mirrors energy production from fossil fuels, and which could be integrated into current refinery models. With WARF’s guidance, Dumesic and his team are now focusing on producing drop-in fuels as efficiently and economically as possible with an eye toward industry. A top priority is identifying the specific biofuel feedstocks that are best suited to heterogeneous catalysis reactions. “In technoeconomic analyses of our processes, the major factor that determined the cost of our fuel was the cost of the biomass,” says Dumesic. “Something that GLBRC is in a position to give leadership on is life cycle analysis of feedstocks and the quantities that would be sustainably

produced and at what price.” One of the benefits of heterogeneous catalysis is that it can be successfully used on many different types of biomass. Currently, GLBRC-produced corn stover—a term for the leaves and stalks of corn plants—is the primary feedstock used in Dumesic’s labs. However, he says that others could work just as well depending on their availability. “If the GLBRC, through their analyses, decided that one feedstock was a better energy source in a particular geographic location, our approach can be easily tailored to that,” he says. “I think that’s an area where being part of the GLBRC is very valuable for us.” While much remains to be learned about drop-in fuels and the markets for them, the Dumesic group’s work highlights the diversity of approach that is a hallmark of GLBRC research. Going forward, the Center hopes that a combination of technological innovation and commercial development will help position renewable compounds for use as building blocks in a variety of known fuels and products, as well as others that have yet to be discovered.

WHAT WE KNOW NOW Replacing the Whole Barrel In their 2012 report, Replacing the Whole Barrel to Reduce U.S. Dependence on Oil the DOE described the importance of developing renewable alternatives to petroleum products in addition to gasoline. Biomass-derived platform chemicals like furfural and levulinic acid are multi-purpose compounds than can be channeled toward fuel production, or converted to many other useful products traditionally manufactured from petrochemicals. According to the DOE report, ethanol can displace the 40 percent of a barrel of crude oil used to produce liquid transportation fuels for ‘light duty’ vehicles like cars—essentially, gasoline. The remaining 60 percent of the barrel goes toward fuels for heavy-duty transportation, such as diesel and jet fuels, as well as a miscellaneous category of ‘other products’ derived from petroleum for both industry and household use. These include glues, cleaners, solvents, resins, plastics and textiles. Platform chemicals can help add value to biofuel production by broadening the range of commodities that can be manufactured from biomass. At the GLBRC, researchers are working to develop technologies that will streamline the production of these renewable chemicals in order to make them more cost-effective for industrial integration. Thus, the ultimate goal is to “replace the whole barrel” of crude oil with a combination of renewable compounds that can both power vehicles and produce everyday necessities efficiently and sustainably.

“Since only about 40 percent of a barrel of crude goes toward conventional petroleum gasoline, we need to move beyond gasoline additives like ethanol and develop technologies that will help us displace diesel, jet fuel, heavy distillates, and a range of other chemicals and products.” Valerie Sarisky-Reed Manager, Biomass Program (Acting) Office of Energy Efficiency and Renewable Energy

2012 Science Report

Spinning Straw into Gold with Co-Products

Waste not, want not: As this cross-section of a corn stem reveals, lignin—stained red—accounts for a significant portion of the plant tissue. GLBRC researchers are looking for ways to use that lignin to their advantage. Photo by John Sedbrook, Illinois State University.

magine if a lemonade stand vendor could market both the lemon peels and the juice. With this approach, he could sell more while wasting less. At the GLBRC, that’s exactly the kind of reasoning researchers are using to transform lignin from biofuel baggage into a benefit.

Lignin is an organic polymer that makes up a third of all plant biomass. While an advantage for plants, lignin poses a challenge for biofuels researchers, who must work out how to break down biomass for conversion to liquid transportation fuels. “We are very focused on using sugars derived from plant cell walls for biofuel,” says GLBRC Science Programs Manager Steven Slater. “But if you’re going to make the process economical, you can’t throw away a third of the material.” That’s why a GLBRC-wide effort is underway to identify ways to turn lignin into useful chemicals and materials that can be sold as ‘co-products’ of biofuel processing. Until recently, bioenergy researchers had thought of lignin primarily as a barrier to large-scale biofuel production. Its structure is irregular and complex, and it varies among plant species. However, as scientists learn more about lignin’s chemical properties and commercial applications, they see great potential for this tricky compound to add value to biofuel reactions as co-products. “What we’re trying to do is get energy out of biomass,” says Slater. “Ideally, we’d like to get all energy as liquid fuel, because you

can put it into a jet or a car. But co-products are a way to add value to the process, and they allow you to take full advantage of all biomass.” As a co-product, lignin can be harnessed for both fuel and non-fuel uses. During some biomass pretreatments, lignin can be extracted and used to coat animal feed pellets. This compacts the feed, making it easier to transport. Lignin can also be burned to provide power, and since it is renewable and its combustion poses no significant environmental threat, it is an excellent candidate to drive ethanol-processing reactions. In James Dumesic’s lab at UW– Madison, researchers have found that burning lignin for power isn’t the only way it can be used to improve the sustainability of biofuel production. Dumesic and his team have been converting lignin into organic solvents, which are used to process biomass into highvalue chemicals traditionally derived from petroleum. Solvents represent a critical step in these chemically catalyzed reactions, and those derived from lignin can replace expensive, non-renewable chemicals. “We have made a mixture of phenols

Great Lakes Bioenergy Research Center from lignin and used them as solvents for our reactions, and they work very well,” says Dumesic. “They are just as efficient as petroleum-based solvents, and they alleviate the need to ship in solvents based on petroleum from a refinery site.” While not classified as co-products because they are used in biomass processing reactions rather than sold, solvents are another example of lignin’s potential to make biofuel production systems less costly and more sustainable. Researchers have also discovered that aromatics, the molecular building blocks of lignin, are key components of many common synthetic materials like plastics. As the only renewable source of aromatics, lignin could potentially be used to generate more sustainable forms of these materials. In order to extract aromatics from lignin, David Hodge, a GLBRC researcher based at Michigan State University, is working on a pretreatment process that involves soaking plant biomass in hydrogen peroxide. This pretreatment approach, called alkaline hydrogen peroxide or AHP, shows promise for simultaneously ‘digesting’ biomass and extracting lignin for use in co-products. “Generating sustainable compounds that could be used to produce analogs of terephthalic acid would be the holy grail for aromatics,” says Hodge. “This petroleum-derived chemical is used to produce certain plastics, which have a global market of several billion pounds per year. The aromatic acids released from the AHP process may offer some promise for producing these compounds.” Ultimately, the true value of lignin co-products is that they lend flexibility to biofuel production and marketing. Since biomass is not currently considered a highvalue commodity, it is fairly inexpensive to obtain large quantities for biofuel processing. However, if a large-scale cellulosic biofuel system were adopted, more feedstock would be demanded to keep up with energy production, which would result in rising feedstock prices. “A feedstock might be free now, but if you develop it, it’s not going to stay free,” says Slater. He explains that producing fuels and valuable chemicals is an economic balancing act that can be affected by changing prices for feedstock and other inputs. Co-products are one way to give farmers and biofuel producers more choice when it comes to marketing. “Co-products help the economics of the

system, because the processed biomass has more than one market and producers aren’t beholden to one or the other,” says Slater. “It means you can send the various products of your process toward the most profitable endpoint at the time.” In the end, Using sodium hydroxide to extract lignin (shown above) from corn decisions about stover is one technique that researchers are combining with tradiwhat to do with tional alkaline pretreatment processes. Photo by Muyang Li, MSU. co-products are all about making biofuel production environmentally and ecoresearchers, lignin may be transformed into nomically sustainable. something even more valuable: an approach “There is a saying in the biofuel busito producing biofuel with benefits for both ness that you can make anything out of conservation and commerce. lignin except money,” says Slater. That may be so, but with the innovations of GLBRC

WHAT WE KNOW NOW Pretreatment, Deconstruction and Co-Products In the past, lignin’s irregular and complex molecular structure made it difficult for scientists to understand and control in order to prepare biomass for fermentation to ethanol. But since lignin makes up fully one-third of all plant matter, GLBRC researchers decided that it was more efficient to find ways to work with lignin rather than against it. Turning lignin into useable co-products requires efficiently separating it from the rest of biomass during biofuel processing reactions. Lignin extraction can occur during biomass pretreatment, a process by which researchers use combinations of physical and chemical methods to break down raw plant material. Below are three different pretreatment technologies currently being developed by GLBRC researchers, each of which affects how lignin can be separated and used: AFEXTM: Ammonia fiber expansion, or AFEXTM, is a pretreatment in which ammonia is used to degrade biomass prior to fermentation. The process causes lignin to form a sticky, dark film over the surface of the pretreated biomass. This stickiness aids in packing the loose plant matter into a denser form, such as pellets, for more efficient transportation. The AFEXTM process was developed and trademarked in the Biomass Conversion Research Laboratory (BCRL) at Michigan State University. E-AFEX: Extractive ammonia fiber expansion, or E-AFEX, is a process also developed at BCRL. The E-AFEX technique is similar to AFEXTM, but it involves using a greater ratio of ammonia to biomass. This approach can convert cellulose to a more easily hydrolyzed form and reduce enzyme requirements, but the impact on lignin is particularly significant. Instead of ending up as a thin layer on top of the biomass after pretreatment, E-AFEX lignin is completely separated from the rest of the plant material, which proceeds down the pipeline to fermentation. The separated lignin can then be channeled into co-products. AHP: Alkaline hydrogen peroxide, or AHP, is another form of pretreatment that uses sodium hydroxide and hydrogen peroxide, rather than ammonia, to help deconstruct biomass to sugars. As a result of AHP pretreatment, lignin may be broken down into aromatic subunits, which can be used to generate compounds with a variety of commercial applications including resins, pigments and plastics. At Michigan State University, researchers are introducing metal catalysts to AHP pretreatment processes to not only improve biomass breakdown, but also generate aromatic molecules that can more easily be recovered for conversion to higher-value products.

2012 Science Report

Getting to Know Our Team: Four Conversations Over 400 scientists, students and staff drive GLBRC research. In the profiles below, you’ll hear from four scientists representing our Deconstruction, Conversion, and Sustainability Research Areas, each of them focusing on a different part of the pipeline that turns cellulosic biomass into ethanol and other advanced biofuels.

Brianna Laube, Graduate Student

Mingjie Jin, Postdoctoral Researcher

Tell us a little about your research: At the Arlington Agricultural Research Station, just north of Madison, I work with Chris Kucharik and Randy Jackson, my two co-advisors. We are looking at the ecological sustainability of biofuels. In particular, I am focusing on the perennial grassland crops, such as switchgrass, a mix of native grass (such as big blue stem and indian grass), and prairie (which has flowers and grasses in it). I’m investigating nitrogen cycling with these grasses. More specifically, I’m trying to determine how plant diversity affects emissions of the greenhouse gas nitrous oxide. What contribution would you like to be able to say that you’ve made to your field in the next ten years? I would like to say that I’ve added some piece of the puzzle to sustainable agriculture, or sustainable biofuels. No one person can say that they’ve solved the whole puzzle, but it’d be awesome if I could contribute a piece. Also, I’d like to help make a bridge between the scientific community and the public, whether that means farmers or the voting public as a whole. What advice would you give to an aspiring scientist? I would tell him or her to get into a science lab, especially if they are at a research university like UW-Madison. You learn a lot more in a lab than you ever can in a classroom. Going to work in a lab was one of the best decisions I made as an undergrad. Even though I ended up switching out of my first lab and completely changing majors, I learned a lot from the experience. I learned that I didn’t want to study in that field, and I also learned about the scientific process and how labs work.

Where did you earn your degree(s) and what did you study? I obtained my master’s degree in Biochemical Engineering at the Nanjing University of Technology in China in 2008. Then, I came to Michigan State University to pursue my Ph.D. degree in Chemical Engineering and joined Professor Bruce Dale’s group and started to work in the GLBRC. I finished my Ph.D. study in May, 2012 and have continued working in the GLBRC as a postdoc. What inspired you to become a scientist? When I was a kid back in 80s, people around me liked and talked about scientists more than movie stars. Tell us a little about your research: My current research focuses on process engineering for integrating and optimizing biomass conversion process including enzymatic hydrolysis and fermentation. What does your typical day in the lab involve? I discuss and design experiments with my technician and undergraduates, write manuscripts and read literature, discuss scientific questions with my colleagues, perform some experiments and reply to emails.

At the GLBRC/KBS long-term ecological research (LTER) site, Laube explores nitrogen recycling as part of GLBRC’s work on sustainability. Photo by James Tesmer, GLBRC.

Mingjie Jin (left) and GLBRC Deconstruction leader Bruce Dale in the Biomass Conversion Research Lab (BCRL) at Michigan State University. Photo by Harley J. Seeley, MSU.

Great Lakes Bioenergy Research Center

The conversations continue online! Visit our website to view the interactive researcher profiles. Rembrandt Haft, Postdoctoral Researcher

Yaoping Zhang, Senior Scientist

What inspired you to become a scientist? The first time I really felt science was my calling was in high school biology. I was sitting in class and the teacher was talking about human genetic diseases. When he talked about muscular dystrophy, I immediately perked up, because muscular dystrophy runs in my family. After doing the math, I realized that because my mother’s brother had had the disease, I had had a 25 percent chance of having the disease and never making it to age 16. Clearly I didn’t have the disease. That moment was so amazing to me, just that there are these big things in the world, and we can understand them. We can talk about them, we can predict them, and we can even control them. That made the idea of science seem both very powerful and very attractive to me. What is that strangest object located in your workspace? A framed picture of an agarose gel. This picture reminds me that it’s worth persevering and trying things, even if they seem like they’re not going to work. Shortly after I started at the GLBRC, I was talking to one of my supervisors about wanting to clone this unusually large section of DNA. He said that the normal method wouldn’t work. A week later, that second step had worked, and the process was complete! This photo shows the gel that I cut up, and in which I was able to prove it had all the pieces of DNA that I wanted to have in it and it was exactly what I was trying to make.

How were you introduced to fermentation as a field of study? During my graduate research, I joined a lab at the Chinese Agricultural University, which had some of the best fermentation equipment in China at that time. I joined this lab because of my interest in bioenergy research, but I was especially happy to do so because fermentation is actually one of my favorite things to do. What is your role at the GLBRC? I am the head scientist of the Experimental Fermentation Lab, which is a component of the GLBRC’s Microbial Synthetic Biology Laboratory at UW-Madison. The lab examines the performance of engineered microbes used to convert biomass into fuels, while looking for ways to improve their performance. Other labs may look at different materials used to produce fuel, but our lab focuses on fermenting cellulosic biomass to produce ethanol. Our lab’s work is important because microbes can behave differently at different volumes. A microbe might ferment very well in a small flask, but poorly in a large fermenter. This complicates our work, because we work at small scales, but our ultimate goal is to find microbes that perform well at a large, industrial scale.

Postdoctoral researcher Rembrandt Haft’s research focuses on increasing E. coli’s ability to efficiently convert biomass to ethanol.

Zhang and Alex La Reau in the Experimental Fermentation Facility, part of the Center’s Conversion group. Photo by Heather Heggemeier, GLBRC.

2012 Science Report

Streamlining Process Design with Models

Christos Maravelias is working with other GLBRC researchers to help them optimize their processes using a suite of modeling and evaluation tools.

ngineering chemical reactions to produce renewable fuels is no small feat. But, it is only part of the battle: biofuel production must be cheap and efficient enough to compete with fossil fuels, and sustainable enough to achieve the long-term goal of energy independence. Fortunately, GLBRC researchers are using some powerful analytical and computational tools to help them rapidly target problems in their processes and make improvements with less time and effort.

Using process design and technoeconomic evaluation, researchers like Christos Maravelias in the UW–Madison College of Engineering are helping GLBRC scientists map out processes for converting cellulosic biomass to liquid transportation fuels. This approach helps researchers zero in on bottlenecks in their processes that may be driving up costs, sapping energy, or generating toxic byproducts. In the case of converting biomass to the gasoline component butene, a project being conducted in James Dumesic’s lab at UW-Madison, Maravelias used process design and evaluation methods to identify a key bottleneck. With these tools, he was able to work together with the researchers to help accelerate the development of fuels and high-value chemicals from plant biomass. “It turned out that separation of an intermediate product was very costly, requiring a lot of heat and an expensive solvent,” he says. “We provided that feedback, and [the researchers] went back to

the lab and developed an alternative strategy that requires a less expensive catalyst, as well as an easier and cheaper separation method. So, we started with a basic strategy, identified those bottlenecks and developed alternatives.” While these analytical tools can be applied on a small scale to focus on specific conversion technologies, they can also be used to examine the viability of building a commercial biofuel production facility. Before a biofuel production process can make the transition from lab to industry, researchers must determine how much it would cost to set up a commercial facility and run it over time. An important step in these analyses is calculating the minimum selling price, or MSP, of a particular product. The MSP is the price at which a biofuel process can break even; thus, if the market price is higher than the minimum, a profit can be made. “Many technologies are needed to make an integrated biofuel process, and

Great Lakes Bioenergy Research Center once we put them all together, we can identify the ones that need improvement,” says Maravelias. In the future, Maravelias hopes that GLBRC scientists will be able to perform their own analyses to help guide their research. One of his current projects involves developing a computer program that will allow researchers to identify and evaluate different ways to generate a desired product. “We will provide a framework and a suite of tools, and the goal is to have a userfriendly interface so that someone without a background in optimization can go and plug in numbers,” says Maravelias. To generate a given product (for example, biodiesel or ethanol), users of the program will be able to design a blueprint for a new process based on certain desired outcomes, which might include a low selling price, minimal environmental impacts, or reduced energy inputs. “[The program] is going to address high level questions, like ‘I want to produce this product, how should I be doing it?’” says Maravelias. He says the goal of the program is to help users choose the basic building blocks for a successful strategy, such as which biofuel feedstock to work with or what conversion technologies to include. After these decisions have been implemented, experts like Maravelias can step in and conduct more in-depth analyses to evaluate and optimize the processes, bringing them closer to market-readiness. “These methods really allow us to see the big picture, focus on the right problems, and address the most pressing challenges,” says Maravelias. “We are guiding research by answering questions like: what improvements would have the most significant impact, what would lower the price the most? Once these have been answered, then we do another evaluation and move on to the next challenge.”

Fast-growing poplar grown on marginal lands can help meet Congress’s 2022 cellulosic biofuels goal. Photo by J.E. Doll, MSU.

WHAT WE KNOW NOW Availability of Marginal Lands Modeling tools are excellent for performing technoeconomic evaluations, but GLBRC researchers are also using them to extrapolate experimental data over time and space. GLBRC researchers led by Phil Robertson at the MSU Kellogg Biological Station (KBS), and by Cesar Izaurralde at the Pacific Northwest National Laboratory (PNNL) Joint Global Change Research Institute ( JGCRI) published a groundbreaking paper in Nature demonstrating the potential of marginal lands to grow biofuel feedstock— and they couldn’t have done it without models. Lands are described as marginal if they are unproductive for growing food crops. Scientists have long speculated that marginal lands could be used to grow mixed-species cellulosic feedstocks for biofuel production, such as grasses, without displacing land needed for producing food. “Ascertaining the potential to produce biofuels without compromising food production is a significant issue in biofuel research,” says Ilya Gelfand, an MSU post-doctoral researcher and first author on the paper. “However, understanding the environmental impact of widespread biofuel production is also a major unanswered question.” Faced with these questions, Robertson and his team set out to find some answers armed with two decades’ worth of cropping systems data from the Michigan-based KBS long term ecological research (LTER) site. Their results showed that the natural, mixed-species plants from marginal lands— referred to as successional vegetation—produced just as much biomass as traditional feedstocks like corn grain. Notably, they found that growing successional vegetation reaped twice the climate benefits of corn by sequestering more carbon in the soil and reducing fossil fuel consumption. Going further, the researchers calculated how much ethanol could be produced annually from successional vegetation in a ten-state Midwest region. Out of nearly 27 million acres of estimated marginal land, they found 35 locations that could support a biorefinery capable of producing at least 24 million gallons of ethanol per year. All together, the researchers identified enough marginal land to produce a total of 5.5 billion gallons of ethanol per year—or 25 percent of the legislated target for cellulosic biofuels to be reached by 2022. “This study shows a substantial capacity for marginal lands to contribute to U.S. transportation energy needs, while providing substantial climate and perhaps conservation benefits,” says Robertson.

2012 Science Report

Accelerating Agriculture with Multi-Purpose Landscapes

Aerial view of hybrid poplar saplings interplanted with oats as a first-year nursery intercrop, part of the GLBRC / KBS LTER cellulosic biofuels research program. Photo by K. Stepnitz, MSU.

ith more mouths to feed every minute, plenty of gas tanks to fill and finite land and water resources, reimagining agricultural landscapes to provide ample food, fuel and fiber is a tall order.

At Michigan State University, Kurt Thelen is one of many GLBRC researchers focused on tackling this issue head on. Despite the enormity of the challenge, Thelen isn’t fazed. “It is a very exciting time to be involved in agriculture,” says Thelen, an MSU professor of plant, soil and microbial sciences. “I’m optimistic for the future.”  As Center researchers consider which crops to grow, where they’ll be grown, and the new systems, equipment and supply chains that are needed to tie them all together, sustainability is key. Biochemists and engineers explore multiple sugar-to-fuel conversion strategies, while plant breeders and agronomists are working to determine what types of bioenergy crops are most suitable for different landscapes. “One thing that is clear is that biomass is local,” says Thelen. “There are niches for a lot of different types of plants.” Using historical data from sites like

the Kellogg Biological Station’s LTER program and recently established bioenergy test plots in Michigan and Wisconsin, GLBRC researchers have learned more about top crop contenders and are beginning to explore the land management challenges that are on the horizon for farmers. One hallmark characteristic of the so-called ‘gold standard’ biofuel crops like switchgrass and corn stover is their productivity. These crops stand out not just because of their reliable yields, but also because they can be grown in close proximity or close succession to other perennial crops that have the ability to sequester more carbon and improve habitats for local wildlife. The abundance of available U.S. corn stover and the adaptability of switchgrass across a wide range of soil and environmental conditions make these crops excellent cellulosic feedstocks, according to the DOE. Landowners who start to use corn stover as a near-term feedstock will need to carefully balance soil health with

Great Lakes Bioenergy Research Center

biomass yield. from a sustainability stand“As a general rule, you can probably point,” Thelen explains. remove about one-third of stover on most In his work with farmacreage in the Great Lakes Region without ers, Thelen says that he is depleting soil organic matter,” says Thelen. encouraged by the excite“If we start taking more than that, we run ment they show for these that risk, which isn’t sustainable.” types of new opportuniGLBRC researchers are also ties—and possibly also investigating the feasibility of using fastincreased opportunities growing poplar and Miscanthus. Current for profit. challenges for Miscanthus include Modeling and mapestablishing the crop successfully, and ping data have shown that poplar is more difficult to deconstruct than while marginal land may be switchgrass and corn stover. Because of these an option for growing more Corn stover remains on the field to be collected as a cellulosic issues, poplar and Miscanthus are classified biofuel feedstocks, many feedstock at the GLBRC / KBS LTER biofuels research site. as ‘silver standard’ crops. of these acres are in small Photo by J.E. Doll, MSU. Labeling plant species as either gold tracts of 25 acres or so. or silver standards helps researchers charIf biomass on that land acterize their advantages and disadvantages is to be used for cellulosic biofuel it will speaks to the need for sustainable energy as bioenergy sources, but the simplicity of need to be compiled or aggregated, which technologies that can support a growing dropping feedstocks into tidy categories Thelen says creates an opportunity for population over the long-term. does not reflect the complex reality of growcustom equipment operators to do plantPredictions estimate that by 2020, ing them in the ground. Once regional feeding or harvesting of new energy crops. farmers must increase crop yields by 40 stock species are determined, the next step is “Farmers with less acreage don’t typpercent to support the world’s food, fiber to find a formula for growing them successically fork over the money for a quarand fuel consumption. In order to meet this fully in a way that benefits not only landter-million dollar self-propelled combine,” need, an additional 10 percent of land area owners and energy producers, but also the Thelen says. “They are already reaching out will be required. land itself. to custom operators who are equipped to “You can design a system that is ecoThelen notes that land management plant or harvest.” nomical and protective of the environment strategies under discussion often involve Thelen imagines that biofuels harfrom a scientific standpoint, but the chalasking the land to vest, aggregation and lenge is making it fit in with the needs and multitask — either “You can design a system that processing scenarios goals of landowners,” Thelen says. by integrating perencould easily follow However, if there is one thing the is economical and protective of nials into the usual the developmental GLBRC knows about, it is taking a chalthe environment from a scientific pattern of other small lenge and turning it into an opportunity. crop rotation, or by planting winter standpoint, but the challenge is farm agriculture and Multi-purpose landscapes present the tantaannuals in between livestock operations. lizing possibility of producing much-needed making it fit in with the needs and primary crops like “The whole idea renewable fuel in a manner that supports goals of landowners,” Thelen says. of local depot centers both farmers and their lands. corn. This approach, called double cropis very well grounded “By some estimates, Michigan alone ping, could allow landowners to reap addiin reality,” he says. “That’s what we have now has four million acres of abandoned farmtional revenue from the sale of cellulosic for agricultural commodities, and that’s what land, located primarily in the northern biomass for fuel while they continueto grow we have for local grain elevators.” lower peninsula,” Thelen says. “These soils food crops. Thelen hopes that these food industry are marginal for food crop production, but In other cases, maintaining a balance systems can serve as models for local well suited for a perennial grass or short between profitability and sustainability may biomass processing centers, which could rotation woody biomass system. By virtue be all in the timing. Thelen explains that take responsibility for pre-processing and of our geography, the Great Lakes Region when perennial feedstocks like switchgrass compacting biomass for shipping and has potential for being a significant player are harvested in their prime, they contain conversion to fuel. in the emerging bioeconomy.” abundant nutrients that can be used to “It is very intuitive that bioenergy crops nourish livestock. But bioenergy harvest would evolve the same way as the food occurs at the end of the growing season, system has. The food system evolved that after plants have naturally moved nutrients way for a reason: because it works…and so to their roots — meaning these valuable we could use the same advantageous stratenutrients remain in the farmer’s soil for gies to handle bioenergy crops,” says Thelen. another fertile growing season. Ultimately, the inspiration behind syn“In terms of bioenergy, it is a benefit for ergistic and ‘multi-purpose’ biofuel strategies the farmer to keep those nutrients in the soil, like double cropping, marginal lands, and which is why perennial crops are so useful integration into existing agricultural systems

2012 Science Report

Collaboration, Technology and Commercialization GLBRC Celebrates First Issued Patent Last summer, the Center was pleased to announce the first patent issued on a GLBRC technology, which was developed from research at Middleton, Wisconsin-based industry partner C5•6 Technologies. The pioneering piece of intellectual property protects a new heattolerant enzyme capable of breaking down the sturdy plant cell walls of cellulosic biomass for conversion to biofuel. Produced by a species of bacteria called Dictyoglomus turgidum, the enzyme is found in the hot springs of Russia’s remote Kamchatka Peninsula. Microbial samples of D. turgidum from Kamchatka and the Obsidian Hot Spring at Yellowstone National Park were sequenced by the DOE Joint Genome Institute. At C5•6, Chief Scientific Officer Phil Brumm and his team have developed methods to produce the enzyme under laboratory conditions. The goal of these techniques is to generate the enzyme for use in large-scale biofuel production in the next few years. The patent signifies the maturation of the GLBRC as a facilitator of technological innovation and transfer, and it is expected that the rate of intellectual property advancement will continue to accelerate following this milestone. “The GLBRC is making significant progress in the field of new enzymes,” says Brumm. “I think that this is just the tip of the iceberg, and that we’ll be seeing more patents in this area at the GLBRC in the next year or two.”

Partnership Tackles Biomass Breakdown with GLBRC Technology On January 3, GLBRC’s ammonia fiber expansion pretreatment technology (AFEXTM) became the focus of a new partnership between biotechnology de-risking and scale-up company MBI and industrial enzyme producer Novozymes. The DOE awarded the two companies a combined $2.5 million to develop enzymes that can efficiently deconstruct AFEXTM -pretreated biomass, with the goal of releasing the fermentable sugars that drive ethanol production. “There are two major challenges in converting agricultural biomass into biobased products,” said Allen Julian, chief business officer of MBI. “One is the challenge of handling, storing and hauling low-density biomass to the refinery, and the other is the challenge of breaking down the biomass Bruce Dale (left), head of Michigan State University’s Biomass Conversion cost-effectively into its constituent sugars.” Research Laboratory, and Bobby Bringi (right), CEO of MBI. AFEXTM tackles both these challenges. The process can be carried out in depots located near farms, with pretreated biomass becoming dense for easy storage and transportation. It also modifies the structure of plant cells, allowing enzymes to more easily break them down into simple sugars. This partnership has the potential to further accelerate the application of the AFEXTM technology to large-scale biofuel production, following DOE’s previous award of $4.3 million to MBI to support the development of a commercial scale AFEXTM pilot reactor at its Lansing, Michigan facility.

Science and Law Connect in Campus Collaboration At the UW–Madison Law and Entrepreneurship (L&E) Clinic, student attorneys are working directly with GLBRC scientists to help focus their research by generating ‘freedom to operate analyses’ identifying pre-existing publications and patents. With the L&E Clinic’s free services, researchers can visualize a research landscape in terms of what is known and unknown, and what areas are open to new discovery, allowing them to plan their work in a more strategic manner to produce results that are both novel ions and marketable. licat b u p / 28 2009

1 20

u 1p

t ica

Great Lakes Bioenergy Research Center

New Biorenewables Technology Moves Closer to Marketplace Following the announcement of Center’s first patent, the first license on a GLBRC technology was finalized in October. Developed in the laboratory of Conversion Area researcher Ron Raines, the technology has been licensed in an agreement between the Wisconsin Alumni Research Foundation (WARF) and biotechnology startup Hyrax Energy—the first company to emerge from GLBRC research. The technology is a novel, renewable biofuel production method that uses ionic liquids to break down cellulosic biomass into fermentable sugars. Notably, the process does not require enzymes or costly pretreatments. “Doing the entire conversion process in ionic liquids eliminates enzymes, pretreatment steps and harsh energy inputs and leads to a dramatic reduction in process complexity and capital intensity,” says Raines. “Hyrax has done considerable market research into the cost of ionic liquids and developed a process model that has been ns tio validated by third parties. The economic advantages of this approach far a lic outweigh the costs.” ub p 1 In addition to its scientific significance and economic 32 / advantages, the licensing of the new technology marks a major 12 20 step toward commercializing this approach to biofuel production on an industrial scale.

1 01

3 01

ion

t ica

u 5p

u 2p

Research Outputs at a Glance

Over the past five years, an innovative approach to funding basic research has propelled GLBRC researchers into new collaborative teams. The results of those new partnerships have yielded tremendous impacts–both in scholarly publications and intellectual property.

400 + Publications 60 Invention Disclosures 58 Patent Applications 17 Licenses Learn more about GLBRC technologies at glbrc.org/technologies

ti ica

2012 Science Report

Enriching Education LabChat Q&A: Biofuels of the Future

Computer Game Simulates Biofuel Production

The GLBRC Communications team explored new outreach territory in September by hosting a DOE LabChat on Twitter. Featuring GLBRC Conversion Area researcher Brian Pfleger and moderated by Education and Outreach Director John Greenler, the LabChat invited questions from the Twitterverse on the theme, “Biofuels of the Future.” Pfleger and Greenler’s expertise met a lively and engaged Twitter audience, who provided a steady stream of questions and comments. Topics of discussion included the science, social impacts, and policy behind biofuels research, with a focus on Pfleger’s specialties of synthetic biology and metabolic engineering. View a Storify recap of the chat.

GLBRC’s Education and Outreach team is turning to technology to make learning about bioenergy more interactive. Over the last year, E&O staff members have been working with Wisconsin Institutes for Discovery (WID) faculty to develop a multi-player computer game that simulates the bioenergy crop production cycle, complete with market pressures and sustainability factors. Players take on the role of a farmer and decide which biofuel feedstocks to plant and sell, with an index of environmental, social, and financial success indicating their scores. The game, which grew out of UW-Madison Computer Science course CS 699, has been developed in collaboration with students and education experts and is now being demonstrated to test audiences. Leith Nye, GLBRC’s education and outreach specialist, believes that the game has educational benefits that could facilitate the development of new skills and the creation of new knowledge. “Games can engage students in exploration and education outside the classroom,” says Nye. Future goals for the software-based simulation include a web version and potential social media applications to provide opportunities to communicate and learn about energy. “Our hope is that people playing the game with this information about economics and sustainability will have to figure out: are there ways to do well at both?” says Ben Shapiro, a scientist in the WID Educational Research group and an instructor for CS 699. “It’s hard to have conversations about these ideas in the abstract, but a game can elicit a lot of discussion.”

Greenler (left) and Pfleger during GLBRC’s LabChat. WBI @WI_bioenergy 26 Sep What has been your proudest accomplishment as a bioenergy researcher? #LabChat Expand

GreatLakesBioenergy @GLBioenergy Graduating 1 PhD student so far with many on the way! Hopefully they’ll contribute to solving the world’s energy challenges too. #LabChat

26 Sep

WBI @WI_bioenergy Brian, what advice would you give to aspiring scientists? #LabChat

26 Sep

Expand

GreatLakesBioenergy @GLBioenergy 26 Sep Never stop asking questions--question everything! Never stop learning. #LabChat Expand

Energy Department @Energy 26 Sep Great question. MT @aaronsauers: @GLBioenergy What modeling/simulation tools do you use in biofuel R&D? Is there open source dev? #LabChat Expand

GreatLakesBioenergy @GLBioenergy 26 Sep Many sim techs. In my lab we use genome-scale metabolic models, kinetic models of cell behavior & technoecon process models. #LabChat Expand

Researchers test out the new biofuels farming computer game at the Wisconsin Institutes for Discovery on the UW-Madison campus. Photo by Celia Luterbacher, GLBRC.

Great Lakes Bioenergy Research Center

Biofuels for Teens

Staying Ahead of the Curve

Over the last year, the Education and Outreach team has been following the work of Waterford, Wisc. high school teacher Craig Kohn, an alumnus of GLBRC’s Research Experience for Teachers and Bioenergy Institute for Educators. Kohn has taken his experience shadowing GLBRC researchers in the lab and added his own educational expertise to create a hands-on laboratory activity for his students. The activity involves ‘bioprospecting,’ or searching for biologically significant organisms. Kohn’s approach takes students into their own backyards and gardens to search for and identify microbes that secrete cellulose-degrading enzymes, which could be useful in breaking down biomass for fuel. Kohn has been working with E&O staff to catalog his activity and make it available via the GLBRC website. Watch a slideshow about the bioprospecting activity.

The GLBRC Education and Outreach team has produced a report designed to support K-12 teachers in their adoption of the soon-to-be-released Next Generation Science Standards (NGSS). The new standards are outlined in the National Resource Council’s (NRC) 2012 Framework for K-12 Science Education. Based on the Framework’s three key dimensions for engaging students—(1) scientific and engineering practices, (2) crosscutting concepts, and (3) disciplinary core ideas—the E&O report highlights specific GLBRC classroom activity packages and professional development programs that can help educators address the coming changes to science education and evaluation. The E&O team’s goal is to support the nation’s teachers by providing them with resources that exemplify the more rigorous and varied scientific experiences envisioned in the NRC Framework. View the report on the E&O webpage.

Leaf-cutter ants (Atta cephalotes) are one of the first species GLBRC has targeted for bioprospecting. In Cameron Currie’s UW–Madison lab, researchers study the cellulose-degrading properties of a fungus that grows on the ants’ leaf cuttings. Photo by B.W. Hoffmann.

GLBRC resources like the E&O report and the annual Bioenergy Institute for Educators program (pictured above) are designed to help K-12 teachers foster excellence and engagement in science education. Photo by John Greenler, GLBRC.

Find Us

Website

GLBRC.org

Newsletter

GLBRC.org/newsletter

Twitter

Facebook

@GLBioenergy

GLBioenergy

Education & Outreach John Greenler jgreenler@glbrc.wisc.edu

Operations Dan Lauffer dlauffer@glbrc.wisc.edu

Media Margaret Broeren mbroeren@glbrc.wisc.edu

Technology Dan Lauffer dlauffer@glbrc.wisc.edu

Credits Published by the U.S. Department of Energy’s Great Lakes Bioenergy Research Center (GLBRC) Produced by the GLBRC Communications Department Writers: Margaret Broeren, Celia Luterbacher and Heather Heggemeier Design and Photography (unless otherwise noted): Matthew Wisniewski Cover Photos: Thomas Kuster, USDA Forest Products Lab; Heather Heggemeier; Matthew Wisniewski; Jessica Will, University of Georgia and Sarynna Lopez Meza, GLBRC

GLBRC.org